DMA Engine: switch PL330 driver to non-irq-safe runtime PM
Subsystems (20)
A message that is not in the archive (sent off-list or not yet received): CGME20161222121148epcas5p11d4e49a3724e375a989aa173f731346f@epcas5p1.samsung.com
cover DMA Engine: switch PL330 driver to non-irq-safe runtime PM
Hello,
This patchset changes the way the runtime PM is implemented in PL330 DMA engine driver. The main goal of such change is to add support for audio power domain to Exynos5 SoCs (5250, 542x, 5433, probably others) and let it to be properly turned off, when no audio is being used. Switching to non-irq-safe runtime PM is needed to properly let power domain to be turned off (irqsafe runtime PM keeps power domain turned on all the time) and to integrate with clock controller's runtime PM (this cannot be workarounded any other way, PL330 uses clocks from the controller, which belongs to the same power domain).
For more details of the proposed change to PL330 driver see patch #3.
Audio power domain on Exynos5 SoCs contains following hardware modules:
1. clock controller
2. pin controller
3. PL330 DMA controller
4. I2S audio controller
Patches for adding/fixing runtime PM for each of the above device will be handled separately.
Runtime PM patches for clock controllers is possible and has been proposed in the following thread (pending review, patch for runtime PM for Exynos Audio subsystem will be added in v4 soon):
https://www.spinics.net/lists/arm-kernel/msg538122.html
Runtime PM support for Exynos pin controller will be posted soon in a separate thread.
Exynos I2S driver already supports runtime PM, but some fixes are needed for it and they will be also posted soon.
Patches are based on linux-next with my PL330 runtime PM fix patch applied (which I assume will be merged as a fix to v4.10):
https://patchwork.kernel.org/patch/9477695/
Best regards
Marek Szyprowski
Samsung R&D Institute Poland
Patch summary:
Marek Szyprowski (3):
dmaengine: pl330: remove pdata based initialization
dmaengine: Forward slave device pointer to of_xlate callback
dmaengine: pl330: Don't require irq-safe runtime PM
drivers/dma/amba-pl08x.c | 2 +- drivers/dma/at_hdmac.c | 4 +- drivers/dma/at_xdmac.c | 2 +- drivers/dma/bcm2835-dma.c | 2 +- drivers/dma/coh901318.c | 2 +- drivers/dma/cppi41.c | 2 +- drivers/dma/dma-jz4780.c | 2 +- drivers/dma/dmaengine.c | 2 +- drivers/dma/dw/platform.c | 2 +- drivers/dma/edma.c | 4 +- drivers/dma/fsl-edma.c | 2 +- drivers/dma/img-mdc-dma.c | 2 +- drivers/dma/imx-dma.c | 2 +- drivers/dma/imx-sdma.c | 2 +- drivers/dma/k3dma.c | 2 +- drivers/dma/mmp_pdma.c | 2 +- drivers/dma/mmp_tdma.c | 2 +- drivers/dma/moxart-dma.c | 2 +- drivers/dma/mxs-dma.c | 2 +- drivers/dma/nbpfaxi.c | 2 +- drivers/dma/of-dma.c | 20 +++-- drivers/dma/pl330.c | 166 +++++++++++++++++++--------------------- drivers/dma/pxa_dma.c | 2 +- drivers/dma/qcom/bam_dma.c | 2 +- drivers/dma/sh/rcar-dmac.c | 2 +- drivers/dma/sh/shdma-of.c | 2 +- drivers/dma/sh/usb-dmac.c | 2 +- drivers/dma/sirf-dma.c | 2 +- drivers/dma/st_fdma.c | 2 +- drivers/dma/ste_dma40.c | 2 +- drivers/dma/stm32-dma.c | 2 +- drivers/dma/sun4i-dma.c | 2 +- drivers/dma/sun6i-dma.c | 2 +- drivers/dma/tegra20-apb-dma.c | 2 +- drivers/dma/tegra210-adma.c | 2 +- drivers/dma/xilinx/xilinx_dma.c | 2 +- drivers/dma/xilinx/zynqmp_dma.c | 2 +- drivers/dma/zx296702_dma.c | 2 +- include/linux/amba/pl330.h | 35 --------- include/linux/of_dma.h | 17 ++-- 40 files changed, 139 insertions(+), 175 deletions(-) delete mode 100644 include/linux/amba/pl330.h
Signature · 1 line
1.9.1
PATCH 1/3 dmaengine: pl330: remove pdata based initialization
This driver is now used only on platforms which supports device tree, so it is safe to remove legacy platform data based initialization code.
--- drivers/dma/pl330.c | 30 ++++++++---------------------- include/linux/amba/pl330.h | 35 ----------------------------------- 2 files changed, 8 insertions(+), 57 deletions(-) delete mode 100644 include/linux/amba/pl330.h
drivers/dma/pl330.c +8 -22
@@ -22,7 +22,6 @@#include <linux/dma-mapping.h> #include <linux/dmaengine.h> #include <linux/amba/bus.h> -#include <linux/amba/pl330.h> #include <linux/scatterlist.h> #include <linux/of.h> #include <linux/of_dma.h>
@@ -2839,7 +2838,6 @@ static int __maybe_unused pl330_resume(struct device *dev)static int pl330_probe (struct amba_device *adev,const struct amba_id *id) { -struct dma_pl330_platdata *pdat;struct pl330_config *pcfg;struct pl330_dmac *pl330;struct dma_pl330_chan *pch, *_p;
@@ -2849,8 +2847,6 @@ static int __maybe_unused pl330_resume(struct device *dev)int num_chan;struct device_node *np = adev->dev.of_node; - pdat =dev_get_platdata (&adev->dev); - ret =dma_set_mask_and_coherent (&adev->dev,DMA_BIT_MASK (32 ));if (ret)return ret;
@@ -2863,7 +2859,7 @@ static int __maybe_unused pl330_resume(struct device *dev) pd = &pl330->ddma; pd->dev = &adev->dev; - pl330->mcbufsz = pdat ? pdat->mcbuf_sz :0 ; + pl330->mcbufsz =0 ;/* get quirk */ for (i =0 ; i <ARRAY_SIZE (of_quirks); i++)
@@ -2907,10 +2903,7 @@ static int __maybe_unused pl330_resume(struct device *dev)INIT_LIST_HEAD (&pd->channels);/* Initialize channel parameters */ -if (pdat) - num_chan =max_t (int, pdat->nr_valid_peri, pcfg->num_chan); -else - num_chan =max_t (int, pcfg->num_peri, pcfg->num_chan); + num_chan =max_t (int, pcfg->num_peri, pcfg->num_chan); pl330->num_peripherals = num_chan;
@@ -2922,11 +2915,8 @@ static int __maybe_unused pl330_resume(struct device *dev)for (i =0 ; i < num_chan; i++) { pch = &pl330->peripherals[i]; -if (!adev->dev.of_node) - pch->chan.private = pdat ? &pdat->peri_id[i] :NULL ; -else - pch->chan.private = adev->dev.of_node; + pch->chan.private = adev->dev.of_node;INIT_LIST_HEAD (&pch->submitted_list);INIT_LIST_HEAD (&pch->work_list);INIT_LIST_HEAD (&pch->completed_list);
@@ -2939,15 +2929,11 @@ static int __maybe_unused pl330_resume(struct device *dev)list_add_tail (&pch->chan.device_node, &pd->channels); } -if (pdat) { - pd->cap_mask = pdat->cap_mask; - }else { -dma_cap_set (DMA_MEMCPY , pd->cap_mask); -if (pcfg->num_peri) { -dma_cap_set (DMA_SLAVE , pd->cap_mask); -dma_cap_set (DMA_CYCLIC , pd->cap_mask); -dma_cap_set (DMA_PRIVATE , pd->cap_mask); - } +dma_cap_set (DMA_MEMCPY , pd->cap_mask); +if (pcfg->num_peri) { +dma_cap_set (DMA_SLAVE , pd->cap_mask); +dma_cap_set (DMA_CYCLIC , pd->cap_mask); +dma_cap_set (DMA_PRIVATE , pd->cap_mask); } pd->device_alloc_chan_resources = pl330_alloc_chan_resources;
include/linux/amba/pl330.h deleted +0 -35
@@ -1,35 +0,0 @@ -/* linux/include/linux/amba/pl330.h -* -* Copyright (C) 2010 Samsung Electronics Co. Ltd. -* Jaswinder Singh <[email protected]> -* -* This program is free software; you can redistribute it and/or modify -* it under the terms of the GNU General Public License as published by -* the Free Software Foundation; either version 2 of the License, or -* (at your option) any later version. -*/ - -#ifndef __AMBA_PL330_H_ -#define __AMBA_PL330_H_ - -#include <linux/dmaengine.h> - -struct dma_pl330_platdata { -/* -* Number of valid peripherals connected to DMAC. -* This may be different from the value read from -* CR0, as the PL330 implementation might have 'holes' -* in the peri list or the peri could also be reached -* from another DMAC which the platform prefers. -*/ -u8 nr_valid_peri; -/* Array of valid peripherals */ -u8 *peri_id; -/* Operational capabilities */ -dma_cap_mask_t cap_mask; -/* Bytes to allocate for MC buffer */ -unsigned mcbuf_sz; -}; - -extern bool pl330_filter (struct dma_chan *chan,void *param); -#endif /* __AMBA_PL330_H_ */
Signature · 1 line
1.9.1
PATCH 2/3 dmaengine: Forward slave device pointer to of_xlate callback
In reply to Marek SzyprowskiAdd pointer to slave struct device to of_dma_xlate to let DMA engine driver to know which slave device is using given DMA channel. This will be later used to implement non-irqsafe runtime PM for DMA engine driver.
--- drivers/dma/amba-pl08x.c | 2 +- drivers/dma/at_hdmac.c | 4 ++-- drivers/dma/at_xdmac.c | 2 +- drivers/dma/bcm2835-dma.c | 2 +- drivers/dma/coh901318.c | 2 +- drivers/dma/cppi41.c | 2 +- drivers/dma/dma-jz4780.c | 2 +- drivers/dma/dmaengine.c | 2 +- drivers/dma/dw/platform.c | 2 +- drivers/dma/edma.c | 4 ++-- drivers/dma/fsl-edma.c | 2 +- drivers/dma/img-mdc-dma.c | 2 +- drivers/dma/imx-dma.c | 2 +- drivers/dma/imx-sdma.c | 2 +- drivers/dma/k3dma.c | 2 +- drivers/dma/mmp_pdma.c | 2 +- drivers/dma/mmp_tdma.c | 2 +- drivers/dma/moxart-dma.c | 2 +- drivers/dma/mxs-dma.c | 2 +- drivers/dma/nbpfaxi.c | 2 +- drivers/dma/of-dma.c | 20 ++++++++++++-------- drivers/dma/pl330.c | 3 ++- drivers/dma/pxa_dma.c | 2 +- drivers/dma/qcom/bam_dma.c | 2 +- drivers/dma/sh/rcar-dmac.c | 2 +- drivers/dma/sh/shdma-of.c | 2 +- drivers/dma/sh/usb-dmac.c | 2 +- drivers/dma/sirf-dma.c | 2 +- drivers/dma/st_fdma.c | 2 +- drivers/dma/ste_dma40.c | 2 +- drivers/dma/stm32-dma.c | 2 +- drivers/dma/sun4i-dma.c | 2 +- drivers/dma/sun6i-dma.c | 2 +- drivers/dma/tegra20-apb-dma.c | 2 +- drivers/dma/tegra210-adma.c | 2 +- drivers/dma/xilinx/xilinx_dma.c | 2 +- drivers/dma/xilinx/zynqmp_dma.c | 2 +- drivers/dma/zx296702_dma.c | 2 +- include/linux/of_dma.h | 17 +++++++++-------- 39 files changed, 61 insertions(+), 55 deletions(-)
drivers/dma/amba-pl08x.c +1 -1
@@ -2059,7 +2059,7 @@ static struct dma_chan *pl08x_find_chan_id(struct pl08x_driver_data *pl08x, }static struct dma_chan *pl08x_of_xlate (struct of_phandle_args *dma_spec, -struct of_dma *ofdma) +struct of_dma *ofdma,struct device *slave) {struct pl08x_driver_data *pl08x = ofdma->of_dma_data;struct dma_chan *dma_chan;
drivers/dma/at_hdmac.c +2 -2
@@ -1788,7 +1788,7 @@ static bool at_dma_filter(struct dma_chan *chan, void *slave) }static struct dma_chan *at_dma_xlate (struct of_phandle_args *dma_spec, -struct of_dma *of_dma) +struct of_dma *of_dma,struct device *slave) {struct dma_chan *chan;struct at_dma_chan *atchan;
@@ -1847,7 +1847,7 @@ static struct dma_chan *at_dma_xlate(struct of_phandle_args *dma_spec, }#else static struct dma_chan *at_dma_xlate (struct of_phandle_args *dma_spec, -struct of_dma *of_dma) +struct of_dma *of_dma,struct device *slave) {return NULL ; }
drivers/dma/at_xdmac.c +1 -1
@@ -508,7 +508,7 @@ static inline void at_xdmac_increment_block_count(struct dma_chan *chan, }static struct dma_chan *at_xdmac_xlate (struct of_phandle_args *dma_spec, -struct of_dma *of_dma) +struct of_dma *of_dma,struct device *slave) {struct at_xdmac *atxdmac = of_dma->of_dma_data;struct at_xdmac_chan *atchan;
drivers/dma/bcm2835-dma.c +1 -1
@@ -877,7 +877,7 @@ static void bcm2835_dma_free(struct bcm2835_dmadev *od)MODULE_DEVICE_TABLE (of, bcm2835_dma_of_match);static struct dma_chan *bcm2835_dma_xlate (struct of_phandle_args *spec, -struct of_dma *ofdma) +struct of_dma *ofdma,struct device *slave) {struct bcm2835_dmadev *d = ofdma->of_dma_data;struct dma_chan *chan;
drivers/dma/coh901318.c +1 -1
@@ -1779,7 +1779,7 @@ static bool coh901318_filter_base_and_id(struct dma_chan *chan, void *data) }static struct dma_chan *coh901318_xlate (struct of_phandle_args *dma_spec, -struct of_dma *ofdma) +struct of_dma *ofdma,struct device *slave) {struct coh901318_filter_args args = { .base = ofdma->of_dma_data,
drivers/dma/cppi41.c +1 -1
@@ -932,7 +932,7 @@ static bool cpp41_dma_filter_fn(struct dma_chan *chan, void *param) };static struct dma_chan *cppi41_dma_xlate (struct of_phandle_args *dma_spec, -struct of_dma *ofdma) +struct of_dma *ofdma,struct device *slave) {int count = dma_spec->args_count;struct of_dma_filter_info *info = ofdma->of_dma_data;
drivers/dma/dma-jz4780.c +1 -1
@@ -707,7 +707,7 @@ static bool jz4780_dma_filter_fn(struct dma_chan *chan, void *param) }static struct dma_chan *jz4780_of_dma_xlate (struct of_phandle_args *dma_spec, -struct of_dma *ofdma) +struct of_dma *ofdma,struct device *slave) {struct jz4780_dma_dev *jzdma = ofdma->of_dma_data;dma_cap_mask_t mask = jzdma->dma_device.cap_mask;
drivers/dma/dmaengine.c +1 -1
@@ -708,7 +708,7 @@ struct dma_chan *dma_request_chan(struct device *dev, const char *name)/* If device-tree is present get slave info from here */ if (dev->of_node) - chan =of_dma_request_slave_channel (dev->of_node, name); + chan =of_dma_request_slave_channel (dev, name);/* If device was enumerated by ACPI get slave info from here */ if (has_acpi_companion (dev) && !chan)
drivers/dma/dw/platform.c +1 -1
@@ -29,7 +29,7 @@#define DRV_NAME "dw_dmac"static struct dma_chan *dw_dma_of_xlate (struct of_phandle_args *dma_spec, -struct of_dma *ofdma) +struct of_dma *ofdma,struct device *slave) {struct dw_dma *dw = ofdma->of_dma_data;struct dw_dma_slave slave = {
drivers/dma/edma.c +2 -2
@@ -2117,7 +2117,7 @@ static struct edma_soc_info *edma_setup_info_from_dt(struct device *dev, }static struct dma_chan *of_edma_xlate (struct of_phandle_args *dma_spec, -struct of_dma *ofdma) +struct of_dma *ofdma,struct device *slave) {struct edma_cc *ecc = ofdma->of_dma_data;struct dma_chan *chan =NULL ;
@@ -2161,7 +2161,7 @@ static struct edma_soc_info *edma_setup_info_from_dt(struct device *dev, }static struct dma_chan *of_edma_xlate (struct of_phandle_args *dma_spec, -struct of_dma *ofdma) +struct of_dma *ofdma,struct device *slave) {return NULL ; }
drivers/dma/fsl-edma.c +1 -1
@@ -750,7 +750,7 @@ static void fsl_edma_issue_pending(struct dma_chan *chan) }static struct dma_chan *fsl_edma_xlate (struct of_phandle_args *dma_spec, -struct of_dma *ofdma) +struct of_dma *ofdma,struct device *slave) {struct fsl_edma_engine *fsl_edma = ofdma->of_dma_data;struct dma_chan *chan, *_chan;
drivers/dma/img-mdc-dma.c +1 -1
@@ -793,7 +793,7 @@ static irqreturn_t mdc_chan_irq(int irq, void *dev_id) }static struct dma_chan *mdc_of_xlate (struct of_phandle_args *dma_spec, -struct of_dma *ofdma) +struct of_dma *ofdma,struct device *slave) {struct mdc_dma *mdma = ofdma->of_dma_data;struct dma_chan *chan;
drivers/dma/imx-dma.c +1 -1
@@ -1032,7 +1032,7 @@ static bool imxdma_filter_fn(struct dma_chan *chan, void *param) }static struct dma_chan *imxdma_xlate (struct of_phandle_args *dma_spec, -struct of_dma *ofdma) +struct of_dma *ofdma,struct device *slave) {int count = dma_spec->args_count;struct imxdma_engine *imxdma = ofdma->of_dma_data;
drivers/dma/imx-sdma.c +1 -1
@@ -1659,7 +1659,7 @@ static bool sdma_filter_fn(struct dma_chan *chan, void *fn_param) }static struct dma_chan *sdma_xlate (struct of_phandle_args *dma_spec, -struct of_dma *ofdma) +struct of_dma *ofdma,struct device *slave) {struct sdma_engine *sdma = ofdma->of_dma_data;dma_cap_mask_t mask = sdma->dma_device.cap_mask;
drivers/dma/k3dma.c +1 -1
@@ -786,7 +786,7 @@ static int k3_dma_transfer_resume(struct dma_chan *chan)MODULE_DEVICE_TABLE (of, k3_pdma_dt_ids);static struct dma_chan *k3_of_dma_simple_xlate (struct of_phandle_args *dma_spec, -struct of_dma *ofdma) +struct of_dma *ofdma,struct device *slave) {struct k3_dma_dev *d = ofdma->of_dma_data;unsigned int request = dma_spec->args[0 ];
drivers/dma/mmp_pdma.c +1 -1
@@ -993,7 +993,7 @@ static int mmp_pdma_chan_init(struct mmp_pdma_device *pdev, int idx, int irq)MODULE_DEVICE_TABLE (of, mmp_pdma_dt_ids);static struct dma_chan *mmp_pdma_dma_xlate (struct of_phandle_args *dma_spec, -struct of_dma *ofdma) +struct of_dma *ofdma,struct device *slave) {struct mmp_pdma_device *d = ofdma->of_dma_data;struct dma_chan *chan;
drivers/dma/mmp_tdma.c +1 -1
@@ -591,7 +591,7 @@ static bool mmp_tdma_filter_fn(struct dma_chan *chan, void *fn_param) }static struct dma_chan *mmp_tdma_xlate (struct of_phandle_args *dma_spec, -struct of_dma *ofdma) +struct of_dma *ofdma,struct device *slave) {struct mmp_tdma_device *tdev = ofdma->of_dma_data;dma_cap_mask_t mask = tdev->device.cap_mask;
drivers/dma/moxart-dma.c +1 -1
@@ -330,7 +330,7 @@ static struct dma_async_tx_descriptor *moxart_prep_slave_sg( }static struct dma_chan *moxart_of_xlate (struct of_phandle_args *dma_spec, -struct of_dma *ofdma) +struct of_dma *ofdma,struct device *slave) {struct moxart_dmadev *mdc = ofdma->of_dma_data;struct dma_chan *chan;
drivers/dma/mxs-dma.c +1 -1
@@ -747,7 +747,7 @@ static bool mxs_dma_filter_fn(struct dma_chan *chan, void *fn_param) }static struct dma_chan *mxs_dma_xlate (struct of_phandle_args *dma_spec, -struct of_dma *ofdma) +struct of_dma *ofdma,struct device *slave) {struct mxs_dma_engine *mxs_dma = ofdma->of_dma_data;dma_cap_mask_t mask = mxs_dma->dma_device.cap_mask;
drivers/dma/nbpfaxi.c +1 -1
@@ -1096,7 +1096,7 @@ static void nbpf_free_chan_resources(struct dma_chan *dchan) }static struct dma_chan *nbpf_of_xlate (struct of_phandle_args *dma_spec, -struct of_dma *ofdma) +struct of_dma *ofdma,struct device *slave) {struct nbpf_device *nbpf = ofdma->of_dma_data;struct dma_chan *dchan;
drivers/dma/of-dma.c +12 -8
@@ -54,7 +54,8 @@ static struct of_dma *of_dma_find_controller(struct of_phandle_args *dma_spec)* to request channel from the real DMA controller. */ static struct dma_chan *of_dma_router_xlate (struct of_phandle_args *dma_spec, -struct of_dma *ofdma) +struct of_dma *ofdma, +struct device *slave) {struct dma_chan *chan;struct of_dma *ofdma_target;
@@ -71,7 +72,8 @@ static struct dma_chan *of_dma_router_xlate(struct of_phandle_args *dma_spec,if (!ofdma_target)return NULL ; - chan = ofdma_target->of_dma_xlate (&dma_spec_target, ofdma_target); + chan = ofdma_target->of_dma_xlate (&dma_spec_target, ofdma_target, + slave);if (chan) { chan->router = ofdma->dma_router; chan->route_data = route_data;
@@ -103,7 +105,8 @@ static struct dma_chan *of_dma_router_xlate(struct of_phandle_args *dma_spec,*/ int of_dma_controller_register (struct device_node *np,struct dma_chan *(*of_dma_xlate) - (struct of_phandle_args *,struct of_dma *), + (struct of_phandle_args *,struct of_dma *, +struct device *),void *data) {struct of_dma *ofdma;
@@ -229,14 +232,15 @@ static int of_dma_match_channel(struct device_node *np, const char *name,/** * of_dma_request_slave_channel - Get the DMA slave channel -* @np: device node to get DMA request from +* @slave: device to get DMA request from * @name: name of desired channel * * Returns pointer to appropriate DMA channel on success or an error pointer. */ -struct dma_chan *of_dma_request_slave_channel (struct device_node *np, +struct dma_chan *of_dma_request_slave_channel (struct device *slave,const char *name) { +struct device_node *np = slave->of_node;struct of_phandle_args dma_spec;struct of_dma *ofdma;struct dma_chan *chan;
@@ -275,7 +279,7 @@ struct dma_chan *of_dma_request_slave_channel(struct device_node *np, ofdma =of_dma_find_controller (&dma_spec);if (ofdma) { - chan = ofdma->of_dma_xlate (&dma_spec, ofdma); + chan = ofdma->of_dma_xlate (&dma_spec, ofdma, slave); }else { ret_no_channel = -EPROBE_DEFER ; chan =NULL ;
@@ -305,7 +309,7 @@ struct dma_chan *of_dma_request_slave_channel(struct device_node *np,* pointer to appropriate dma channel on success or NULL on error. */ struct dma_chan *of_dma_simple_xlate (struct of_phandle_args *dma_spec, -struct of_dma *ofdma) +struct of_dma *ofdma,struct device *slave) {int count = dma_spec->args_count;struct of_dma_filter_info *info = ofdma->of_dma_data;
@@ -335,7 +339,7 @@ struct dma_chan *of_dma_simple_xlate(struct of_phandle_args *dma_spec,* Returns pointer to appropriate dma channel on success or NULL on error. */ struct dma_chan *of_dma_xlate_by_chan_id (struct of_phandle_args *dma_spec, -struct of_dma *ofdma) +struct of_dma *ofdma,struct device *slave) {struct dma_device *dev = ofdma->of_dma_data;struct dma_chan *chan, *candidate =NULL ;
drivers/dma/pl330.c +2 -1
@@ -2096,7 +2096,8 @@ bool pl330_filter(struct dma_chan *chan, void *param)EXPORT_SYMBOL (pl330_filter);static struct dma_chan *of_dma_pl330_xlate (struct of_phandle_args *dma_spec, -struct of_dma *ofdma) +struct of_dma *ofdma, +struct device *slave) {int count = dma_spec->args_count;struct pl330_dmac *pl330 = ofdma->of_dma_data;
drivers/dma/pxa_dma.c +1 -1
@@ -1336,7 +1336,7 @@ static int pxad_init_phys(struct platform_device *op,MODULE_DEVICE_TABLE (of, pxad_dt_ids);static struct dma_chan *pxad_dma_xlate (struct of_phandle_args *dma_spec, -struct of_dma *ofdma) +struct of_dma *ofdma,struct device *slave) {struct pxad_device *d = ofdma->of_dma_data;struct dma_chan *chan;
drivers/dma/qcom/bam_dma.c +1 -1
@@ -1049,7 +1049,7 @@ static void bam_dma_free_desc(struct virt_dma_desc *vd) }static struct dma_chan *bam_dma_xlate (struct of_phandle_args *dma_spec, -struct of_dma *of) +struct of_dma *of,struct device *slave) {struct bam_device *bdev =container_of (of->of_dma_data, struct bam_device, common);
drivers/dma/sh/rcar-dmac.c +1 -1
@@ -1552,7 +1552,7 @@ static bool rcar_dmac_chan_filter(struct dma_chan *chan, void *arg) }static struct dma_chan *rcar_dmac_of_xlate (struct of_phandle_args *dma_spec, -struct of_dma *ofdma) +struct of_dma *ofdma,struct device *slave) {struct rcar_dmac_chan *rchan;struct dma_chan *chan;
drivers/dma/sh/shdma-of.c +1 -1
@@ -20,7 +20,7 @@#define to_shdma_chan (c) container_of(c, struct shdma_chan, dma_chan)static struct dma_chan *shdma_of_xlate (struct of_phandle_args *dma_spec, -struct of_dma *ofdma) +struct of_dma *ofdma,struct device *slave) {u32 id = dma_spec->args[0 ];dma_cap_mask_t mask;
drivers/dma/sh/usb-dmac.c +1 -1
@@ -650,7 +650,7 @@ static bool usb_dmac_chan_filter(struct dma_chan *chan, void *arg) }static struct dma_chan *usb_dmac_of_xlate (struct of_phandle_args *dma_spec, -struct of_dma *ofdma) +struct of_dma *ofdma,struct device *slave) {struct dma_chan *chan;dma_cap_mask_t mask;
drivers/dma/sirf-dma.c +1 -1
@@ -826,7 +826,7 @@ bool sirfsoc_dma_filter_id(struct dma_chan *chan, void *chan_id) BIT(DMA_SLAVE_BUSWIDTH_8_BYTES))static struct dma_chan *of_dma_sirfsoc_xlate (struct of_phandle_args *dma_spec, -struct of_dma *ofdma) +struct of_dma *ofdma,struct device *slave) {struct sirfsoc_dma *sdma = ofdma->of_dma_data;unsigned int request = dma_spec->args[0 ];
drivers/dma/st_fdma.c +1 -1
@@ -167,7 +167,7 @@ static irqreturn_t st_fdma_irq_handler(int irq, void *dev_id) }static struct dma_chan *st_fdma_of_xlate (struct of_phandle_args *dma_spec, -struct of_dma *ofdma) +struct of_dma *ofdma,struct device *slave) {struct st_fdma_dev *fdev = ofdma->of_dma_data;struct dma_chan *chan;
drivers/dma/ste_dma40.c +1 -1
@@ -2334,7 +2334,7 @@ static void d40_set_prio_realtime(struct d40_chan *d40c)#define D40_DT_FLAGS_HIGH_PRIO (flags) ((flags >> 4) & 0x1)static struct dma_chan *d40_xlate (struct of_phandle_args *dma_spec, -struct of_dma *ofdma) +struct of_dma *ofdma,struct device *slave) {struct stedma40_chan_cfg cfg;dma_cap_mask_t cap;
drivers/dma/stm32-dma.c +1 -1
@@ -965,7 +965,7 @@ static void stm32_dma_set_config(struct stm32_dma_chan *chan, }static struct dma_chan *stm32_dma_of_xlate (struct of_phandle_args *dma_spec, -struct of_dma *ofdma) +struct of_dma *ofdma,struct device *slave) {struct stm32_dma_device *dmadev = ofdma->of_dma_data;struct stm32_dma_cfg cfg;
drivers/dma/sun4i-dma.c +1 -1
@@ -909,7 +909,7 @@ static int sun4i_dma_config(struct dma_chan *chan, }static struct dma_chan *sun4i_dma_of_xlate (struct of_phandle_args *dma_spec, -struct of_dma *ofdma) +struct of_dma *ofdma,struct device *slave) {struct sun4i_dma_dev *priv = ofdma->of_dma_data;struct sun4i_dma_vchan *vchan;
drivers/dma/sun6i-dma.c +1 -1
@@ -930,7 +930,7 @@ static void sun6i_dma_free_chan_resources(struct dma_chan *chan) }static struct dma_chan *sun6i_dma_of_xlate (struct of_phandle_args *dma_spec, -struct of_dma *ofdma) +struct of_dma *ofdma,struct device *slave) {struct sun6i_dma_dev *sdev = ofdma->of_dma_data;struct sun6i_vchan *vchan;
drivers/dma/tegra20-apb-dma.c +1 -1
@@ -1239,7 +1239,7 @@ static void tegra_dma_free_chan_resources(struct dma_chan *dc) }static struct dma_chan *tegra_dma_of_xlate (struct of_phandle_args *dma_spec, -struct of_dma *ofdma) +struct of_dma *ofdma,struct device *slave) {struct tegra_dma *tdma = ofdma->of_dma_data;struct dma_chan *chan;
drivers/dma/tegra210-adma.c +1 -1
@@ -605,7 +605,7 @@ static void tegra_adma_free_chan_resources(struct dma_chan *dc) }static struct dma_chan *tegra_dma_of_xlate (struct of_phandle_args *dma_spec, -struct of_dma *ofdma) +struct of_dma *ofdma,struct device *slave) {struct tegra_adma *tdma = ofdma->of_dma_data;struct tegra_adma_chan *tdc;
drivers/dma/xilinx/xilinx_dma.c +1 -1
@@ -2461,7 +2461,7 @@ static int xilinx_dma_child_probe(struct xilinx_dma_device *xdev,* Return: DMA channel pointer on success and NULL on error */ static struct dma_chan *of_dma_xilinx_xlate (struct of_phandle_args *dma_spec, -struct of_dma *ofdma) +struct of_dma *ofdma,struct device *slave) {struct xilinx_dma_device *xdev = ofdma->of_dma_data;int chan_id = dma_spec->args[0 ];
drivers/dma/xilinx/zynqmp_dma.c +1 -1
@@ -1040,7 +1040,7 @@ static int zynqmp_dma_chan_probe(struct zynqmp_dma_device *zdev,* Return: DMA channel pointer on success and NULL on error */ static struct dma_chan *of_zynqmp_dma_xlate (struct of_phandle_args *dma_spec, -struct of_dma *ofdma) +struct of_dma *ofdma,struct device *slave) {struct zynqmp_dma_device *zdev = ofdma->of_dma_data;
drivers/dma/zx296702_dma.c +1 -1
@@ -731,7 +731,7 @@ static void zx_dma_free_desc(struct virt_dma_desc *vd)MODULE_DEVICE_TABLE (of, zx6702_dma_dt_ids);static struct dma_chan *zx_of_dma_simple_xlate (struct of_phandle_args *dma_spec, -struct of_dma *ofdma) +struct of_dma *ofdma,struct device *slave) {struct zx_dma_dev *d = ofdma->of_dma_data;unsigned int request = dma_spec->args[0 ];
include/linux/of_dma.h +9 -8
@@ -22,7 +22,8 @@ struct of_dma {struct list_head of_dma_controllers;struct device_node *of_node;struct dma_chan *(*of_dma_xlate) - (struct of_phandle_args *,struct of_dma *); + (struct of_phandle_args *,struct of_dma *, +struct device *);void *(*of_dma_route_allocate) (struct of_phandle_args *,struct of_dma *);struct dma_router *dma_router;
@@ -37,7 +38,7 @@ struct of_dma_filter_info {#ifdef CONFIG_DMA_OF extern int of_dma_controller_register (struct device_node *np,struct dma_chan *(*of_dma_xlate) - (struct of_phandle_args *,struct of_dma *), + (struct of_phandle_args *,struct of_dma *,struct device *),void *data);extern void of_dma_controller_free (struct device_node *np);
@@ -47,17 +48,17 @@ extern int of_dma_router_register(struct device_node *np, struct dma_router *dma_router);#define of_dma_router_free of_dma_controller_free -extern struct dma_chan *of_dma_request_slave_channel (struct device_node *np, +extern struct dma_chan *of_dma_request_slave_channel (struct device *slave,const char *name);extern struct dma_chan *of_dma_simple_xlate (struct of_phandle_args *dma_spec, -struct of_dma *ofdma); +struct of_dma *ofdma,struct device *slave);extern struct dma_chan *of_dma_xlate_by_chan_id (struct of_phandle_args *dma_spec, -struct of_dma *ofdma); +struct of_dma *ofdma,struct device *slave);#else static inline int of_dma_controller_register (struct device_node *np,struct dma_chan *(*of_dma_xlate) - (struct of_phandle_args *,struct of_dma *), + (struct of_phandle_args *,struct of_dma *,struct device *),void *data) {return -ENODEV ;
@@ -77,14 +78,14 @@ static inline int of_dma_router_register(struct device_node *np,#define of_dma_router_free of_dma_controller_free -static inline struct dma_chan *of_dma_request_slave_channel (struct device_node *np, +static inline struct dma_chan *of_dma_request_slave_channel (struct device *slave,const char *name) {return ERR_PTR (-ENODEV ); }static inline struct dma_chan *of_dma_simple_xlate (struct of_phandle_args *dma_spec, -struct of_dma *ofdma) +struct of_dma *ofdma,struct device *slave) {return NULL ; }
Signature · 1 line
1.9.1
PATCH 3/3 dmaengine: pl330: Don't require irq-safe runtime PM
In reply to Marek SzyprowskiThis patch replaces irq-safe runtime pm with non-irq-safe version.
Till now non-irq-safe runtime PM implementation was only possible by calling pm_runtime_get/put functions from alloc/free_chan_resources. All other DMA engine API functions cannot be called from a context, which allows sleeping. Such implementation in practice resulted in keeping PL330 DMA controller device active almost all the time, because most of the slave device drivers (DMA engine clients) acquired DMA channel in their probe() function and released it during driver removal.
This patch provides a new approach. The main assumption for it is an observation that there can be only one slave device using each DMA channel. Using recently introduced device dependencies (links) infrastructure one can ensure proper runtime PM state of PL330 DMA controller. In this approach in pl330_alloc_chan_resources() function a new dependency is being created between PL330 DMA controller device (as supplier) and given slave device (as consumer). This way PL330 DMA controller device runtime active counter is increased when the slave device is resumed and decreased the same time when given slave device is put to suspend. This way it has been ensured to keep PL330 DMA controller runtime active if there is an active used of any of its DMA channels. Slave device pointer is initially stored in per-channel data in of_dma_xlate callback. This is similar to what has been already implemented in Exynos IOMMU driver in commit 2f5f44f205cc958b ("iommu/exynos: Use device dependency links to control runtime pm").
If one requests memory-to-memory chanel, runtime active counter is increased unconditionally. This might be a drawback of this approach, but PL330 is not really used for memory-to-memory operations due to poor performance in such operations compared to CPU.
Introducing non-irq-safe runtime power management finally allows to turn audio power domain off on Exynos5 SoCs.
Removal of irq-safe runtime pm is based on the revert of the following commits:
1. "dmaengine: pl330: fix runtime pm support" commit <no stable id yet>
2. "dmaengine: pl330: Fix hang on dmaengine_terminate_all on certain boards" commit 81cc6edc08705ac0146fe6ac14a0982a31ce6f3d
3. "ARM: 8202/1: dmaengine: pl330: Add runtime Power Management support v12" commit ae43b3289186480f81c78bb63d788a85a3631f47
--- drivers/dma/pl330.c | 133 +++++++++++++++++++++++++++------------------------- 1 file changed, 70 insertions(+), 63 deletions(-)
drivers/dma/pl330.c +70 -63
@@ -268,9 +268,6 @@ enum pl330_byteswap {#define NR_DEFAULT_DESC 16 -/* Delay for runtime PM autosuspend, ms */ -#define PL330_AUTOSUSPEND_DELAY 20 -/* Populated by the PL330 core driver for DMA API driver's info */ struct pl330_config {u32 periph_id;
@@ -449,7 +446,8 @@ struct dma_pl330_chan {bool cyclic;/* for runtime pm tracking */ -bool active; +struct device *slave; +struct device_link *slave_link; };struct pl330_dmac {
@@ -2015,7 +2013,6 @@ static void pl330_tasklet(unsigned long data)struct dma_pl330_chan *pch = (struct dma_pl330_chan *)data;struct dma_pl330_desc *desc, *_dt;unsigned long flags; -bool power_down = false;spin_lock_irqsave (&pch->lock, flags);
@@ -2030,18 +2027,10 @@ static void pl330_tasklet(unsigned long data)/* Try to submit a req imm. next to the last completed cookie */ fill_queue (pch); -if (list_empty (&pch->work_list)) { -spin_lock (&pch->thread->dmac->lock); -_stop (pch->thread); -spin_unlock (&pch->thread->dmac->lock); - power_down = true; - pch->active = false; - }else { -/* Make sure the PL330 Channel thread is active */ -spin_lock (&pch->thread->dmac->lock); -_start (pch->thread); -spin_unlock (&pch->thread->dmac->lock); - } +/* Make sure the PL330 Channel thread is active */ +spin_lock (&pch->thread->dmac->lock); +_start (pch->thread); +spin_unlock (&pch->thread->dmac->lock);while (!list_empty (&pch->completed_list)) {struct dmaengine_desc_callback cb;
@@ -2054,13 +2043,6 @@ static void pl330_tasklet(unsigned long data)if (pch->cyclic) { desc->status =PREP ;list_move_tail (&desc->node, &pch->work_list); -if (power_down) { - pch->active = true; -spin_lock (&pch->thread->dmac->lock); -_start (pch->thread); -spin_unlock (&pch->thread->dmac->lock); - power_down = false; - } }else { desc->status =FREE ;list_move_tail (&desc->node, &pch->dmac->desc_pool);
@@ -2075,12 +2057,6 @@ static void pl330_tasklet(unsigned long data) } }spin_unlock_irqrestore (&pch->lock, flags); - -/* If work list empty, power down */ -if (power_down) { -pm_runtime_mark_last_busy (pch->dmac->ddma.dev); -pm_runtime_put_autosuspend (pch->dmac->ddma.dev); - } }bool pl330_filter (struct dma_chan *chan,void *param)
@@ -2113,14 +2089,63 @@ static struct dma_chan *of_dma_pl330_xlate(struct of_phandle_args *dma_spec,if (chan_id >= pl330->num_peripherals)return NULL ; +if (!pl330->peripherals[chan_id].slave) + pl330->peripherals[chan_id].slave = slave; +else if (pl330->peripherals[chan_id].slave != slave) { +dev_err (pl330->ddma.dev, +"Can't use same channel with multiple slave devices!\n" ); +return NULL ; + } +return dma_get_slave_channel (&pl330->peripherals[chan_id].chan); } +static int pl330_add_slave_link (struct pl330_dmac *pl330, +struct dma_pl330_chan *pch) +{ +struct device_link *link; +int i; + +if (pch->slave_link) +return 0 ; + + link =device_link_add (pch->slave, pl330->ddma.dev, +DL_FLAG_PM_RUNTIME |DL_FLAG_RPM_ACTIVE ); +if (!link) +return -ENODEV ; + +for (i =0 ; i < pl330->num_peripherals; i++) +if (pl330->peripherals[i].slave == pch->slave) + pl330->peripherals[i].slave_link = link; +return 0 ; +} + +static void pl330_del_slave_link (struct pl330_dmac *pl330, +struct dma_pl330_chan *pch) +{ +struct device_link *link = pch->slave_link; +int i, count =0 ; + +for (i =0 ; i < pl330->num_peripherals; i++) +if (pl330->peripherals[i].slave == pch->slave && + pl330->peripherals[i].thread) + count++; + +if (count >0 ) +return ; + +device_link_del (link); +for (i =0 ; i < pl330->num_peripherals; i++) +if (pl330->peripherals[i].slave == pch->slave) + pch->slave_link =NULL ; +} +static int pl330_alloc_chan_resources (struct dma_chan *chan) {struct dma_pl330_chan *pch =to_pchan (chan);struct pl330_dmac *pl330 = pch->dmac;unsigned long flags; +int ret =0 ;spin_lock_irqsave (&pch->lock, flags);
@@ -2137,6 +2162,14 @@ static int pl330_alloc_chan_resources(struct dma_chan *chan)spin_unlock_irqrestore (&pch->lock, flags); +if (pch->slave) + ret =pl330_add_slave_link (pl330, pch); +else + ret =pm_runtime_get_sync (pl330->ddma.dev); + +if (ret <0 ) +return ret; +return 1 ; }
@@ -2171,9 +2204,7 @@ static int pl330_terminate_all(struct dma_chan *chan)unsigned long flags;struct pl330_dmac *pl330 = pch->dmac;LIST_HEAD (list); -bool power_down = false; -pm_runtime_get_sync (pl330->ddma.dev);spin_lock_irqsave (&pch->lock, flags);spin_lock (&pl330->lock);_stop (pch->thread);
@@ -2182,8 +2213,6 @@ static int pl330_terminate_all(struct dma_chan *chan) pch->thread->req[0 ].desc =NULL ; pch->thread->req[1 ].desc =NULL ; pch->thread->req_running =-1 ; - power_down = pch->active; - pch->active = false;/* Mark all desc done */ list_for_each_entry (desc, &pch->submitted_list, node) {
@@ -2200,10 +2229,6 @@ static int pl330_terminate_all(struct dma_chan *chan)list_splice_tail_init (&pch->work_list, &pl330->desc_pool);list_splice_tail_init (&pch->completed_list, &pl330->desc_pool);spin_unlock_irqrestore (&pch->lock, flags); -pm_runtime_mark_last_busy (pl330->ddma.dev); -if (power_down) -pm_runtime_put_autosuspend (pl330->ddma.dev); -pm_runtime_put_autosuspend (pl330->ddma.dev);return 0 ; }
@@ -2221,7 +2246,6 @@ static int pl330_pause(struct dma_chan *chan)struct pl330_dmac *pl330 = pch->dmac;unsigned long flags; -pm_runtime_get_sync (pl330->ddma.dev);spin_lock_irqsave (&pch->lock, flags);spin_lock (&pl330->lock);
@@ -2229,8 +2253,6 @@ static int pl330_pause(struct dma_chan *chan)spin_unlock (&pl330->lock);spin_unlock_irqrestore (&pch->lock, flags); -pm_runtime_mark_last_busy (pl330->ddma.dev); -pm_runtime_put_autosuspend (pl330->ddma.dev);return 0 ; }
@@ -2238,11 +2260,11 @@ static int pl330_pause(struct dma_chan *chan)static void pl330_free_chan_resources (struct dma_chan *chan) {struct dma_pl330_chan *pch =to_pchan (chan); +struct pl330_dmac *pl330 = pch->dmac;unsigned long flags;tasklet_kill (&pch->task); -pm_runtime_get_sync (pch->dmac->ddma.dev);spin_lock_irqsave (&pch->lock, flags);pl330_release_channel (pch->thread);
@@ -2252,19 +2274,20 @@ static void pl330_free_chan_resources(struct dma_chan *chan)list_splice_tail_init (&pch->work_list, &pch->dmac->desc_pool);spin_unlock_irqrestore (&pch->lock, flags); -pm_runtime_mark_last_busy (pch->dmac->ddma.dev); -pm_runtime_put_autosuspend (pch->dmac->ddma.dev); + +if (pch->slave) +pl330_del_slave_link (pl330, pch); +else +pm_runtime_put (pl330->ddma.dev); }static int pl330_get_current_xferred_count (struct dma_pl330_chan *pch,struct dma_pl330_desc *desc) {struct pl330_thread *thrd = pch->thread; -struct pl330_dmac *pl330 = pch->dmac;void __iomem *regs = thrd->dmac->base;u32 val, addr; -pm_runtime_get_sync (pl330->ddma.dev); val = addr =0 ;if (desc->rqcfg.src_inc) { val =readl (regs +SA (thrd->id));
@@ -2273,8 +2296,6 @@ static int pl330_get_current_xferred_count(struct dma_pl330_chan *pch, val =readl (regs +DA (thrd->id)); addr = desc->px.dst_addr; } -pm_runtime_mark_last_busy (pch->dmac->ddma.dev); -pm_runtime_put_autosuspend (pl330->ddma.dev);/* If DMAMOV hasn't finished yet, SAR/DAR can be zero */ if (!val)
@@ -2360,16 +2381,6 @@ static void pl330_issue_pending(struct dma_chan *chan)unsigned long flags;spin_lock_irqsave (&pch->lock, flags); -if (list_empty (&pch->work_list)) { -/* -* Warn on nothing pending. Empty submitted_list may -* break our pm_runtime usage counter as it is -* updated on work_list emptiness status. -*/ -WARN_ON (list_empty (&pch->submitted_list)); - pch->active = true; -pm_runtime_get_sync (pch->dmac->ddma.dev); - }list_splice_tail_init (&pch->submitted_list, &pch->work_list);spin_unlock_irqrestore (&pch->lock, flags);
@@ -2987,11 +2998,7 @@ static int __maybe_unused pl330_resume(struct device *dev) pcfg->data_buf_dep, pcfg->data_bus_width /8 , pcfg->num_chan, pcfg->num_peri, pcfg->num_events); -pm_runtime_irq_safe (&adev->dev); -pm_runtime_use_autosuspend (&adev->dev); -pm_runtime_set_autosuspend_delay (&adev->dev,PL330_AUTOSUSPEND_DELAY ); -pm_runtime_mark_last_busy (&adev->dev); -pm_runtime_put_autosuspend (&adev->dev); +pm_runtime_put (&adev->dev);return 0 ; probe_err3:
Signature · 1 line
1.9.1
Krzysztof Kozlowski
maintainerPATCH 3/3 dmaengine: pl330: Don't require irq-safe runtime PM
Quoted 9 lines · Marek Szyprowski
This patch replaces irq-safe runtime pm with non-irq-safe version.
Till now non-irq-safe runtime PM implementation was only possible by calling pm_runtime_get/put functions from alloc/free_chan_resources. All other DMA engine API functions cannot be called from a context, which allows sleeping. Such implementation in practice resulted in keeping PL330 DMA controller device active almost all the time, because most of the slave device drivers (DMA engine clients) acquired DMA channel in their
probe()function and released it during driver removal.
I think that is not accurate (unless something changed recently and I missed it)... The runtime PM in pl330 was infact suspending device when the queue was empty. It was working during the regular work of DMA and slave devices.
Maybe your recent fix changed this?
Quoted 1 line
This patch provides a new approach.
Please say why this approach is better because the previous one - was suspending the dma channel when not used. Otherwise, it would make no sense of implement the irq-safe runtime PM at the beginning!
Of course, a change from irq-safe to non-irq-safe is a good reason to implement changes. But that was not mentioned in the first paragraph at all.
Quoted 2 lines
The main assumption for it is an
observation that there can be only one slave device using each DMA channel.
Wait, observation, real requirement or assumption?
Later in the code I see adding such requirement.
Quoted 4 lines
Using recently introduced device dependencies (links) infrastructure one can ensure proper runtime PM state of PL330 DMA controller. In this approach in
pl330_alloc_chan_resources()function a new dependency is being created between PL330 DMA controller device (as supplier) and given slave device
Quoted 8 lines
(as consumer). This way PL330 DMA controller device runtime active counter is increased when the slave device is resumed and decreased the same time when given slave device is put to suspend. This way it has been ensured to keep PL330 DMA controller runtime active if there is an active used of any of its DMA channels. Slave device pointer is initially stored in per-channel data in
of_dma_xlatecallback. This is similar to what has been already implemented in Exynos IOMMU driver in commit2f5f44f205cc958b("iommu/exynos: Use device dependency links to control runtime pm").
Sounds convincing... Interesting approach!
My doubts are:
1. What with more then one slave device? (assumption?)
2. If slave device does not implement runtime PM, then pl330 will be active all the time?
3. If slave device implements runtime PM in a way that it's enabled in probe and released in remove, then pl330 will be active all the time?
Quoted 8 lines
If one requests memory-to-memory chanel, runtime active counter is increased unconditionally. This might be a drawback of this approach, but PL330 is not really used for memory-to-memory operations due to poor performance in such operations compared to CPU.
Introducing non-irq-safe runtime power management finally allows to turn audio power domain off on Exynos5 SoCs.
... and actually any domain which contained pl330 device so this is nice benefit!
Quoted 97 lines
Removal of irq-safe runtime pm is based on the revert of the following commits:
1. "dmaengine: pl330: fix runtime pm support" commit <no stable id yet>
2. "dmaengine: pl330: Fix hang ondmaengine_terminate_allon certain boards" commit81cc6edc08705ac0146fe6ac14a0982a31ce6f3d
3. "ARM: 8202/1: dmaengine: pl330: Add runtime Power Management support v12" commitae43b3289186480f81c78bb63d788a85a3631f47Signed-off-by Marek Szyprowski <[email protected]>--- drivers/dma/pl330.c | 133 +++++++++++++++++++++++++++------------------------- 1 file changed, 70 insertions(+), 63 deletions(-)drivers/dma/pl330.c +6
-30@@ -268,9 +268,6 @@ enum pl330_byteswap {#define NR_DEFAULT_DESC 16 -/* Delay for runtime PM autosuspend, ms */ -#define PL330_AUTOSUSPEND_DELAY 20 -/* Populated by the PL330 core driver for DMA API driver's info */ struct pl330_config {u32 periph_id;@@ -449,7 +446,8 @@ struct dma_pl330_chan {bool cyclic;/* for runtime pm tracking */ -bool active; +struct device *slave; +struct device_link *slave_link; };struct pl330_dmac {@@ -2015,7 +2013,6 @@ static void pl330_tasklet(unsigned long data)struct dma_pl330_chan *pch = (struct dma_pl330_chan *)data;struct dma_pl330_desc *desc, *_dt;unsigned long flags; -bool power_down = false;spin_lock_irqsave (&pch->lock, flags);@@ -2030,18 +2027,10 @@ static void pl330_tasklet(unsigned long data)/* Try to submit a req imm. next to the last completed cookie */ fill_queue (pch); -if (list_empty (&pch->work_list)) { -spin_lock (&pch->thread->dmac->lock); -_stop (pch->thread); -spin_unlock (&pch->thread->dmac->lock); - power_down = true; - pch->active = false; - }else { -/* Make sure the PL330 Channel thread is active */ -spin_lock (&pch->thread->dmac->lock); -_start (pch->thread); -spin_unlock (&pch->thread->dmac->lock); - } +/* Make sure the PL330 Channel thread is active */ +spin_lock (&pch->thread->dmac->lock); +_start (pch->thread); +spin_unlock (&pch->thread->dmac->lock);while (!list_empty (&pch->completed_list)) {struct dmaengine_desc_callback cb;@@ -2054,13 +2043,6 @@ static void pl330_tasklet(unsigned long data)if (pch->cyclic) { desc->status =PREP ;list_move_tail (&desc->node, &pch->work_list); -if (power_down) { - pch->active = true; -spin_lock (&pch->thread->dmac->lock); -_start (pch->thread); -spin_unlock (&pch->thread->dmac->lock); - power_down = false; - } }else { desc->status =FREE ;list_move_tail (&desc->node, &pch->dmac->desc_pool);@@ -2075,12 +2057,6 @@ static void pl330_tasklet(unsigned long data) } }spin_unlock_irqrestore (&pch->lock, flags); - -/* If work list empty, power down */ -if (power_down) { -pm_runtime_mark_last_busy (pch->dmac->ddma.dev); -pm_runtime_put_autosuspend (pch->dmac->ddma.dev); - } }bool pl330_filter (struct dma_chan *chan,void *param)
drivers/dma/pl330.c static struct dma_chan *of_dma_pl330_xlate(struct of_phandle_args *dma_spec, · line 2098
Quoted 10 lines
drivers/dma/pl330.c +7
-0@@ -2113,14 +2089,63 @@ static struct dma_chan *of_dma_pl330_xlate(struct of_phandle_args *dma_spec,if (chan_id >= pl330->num_peripherals)return NULL ; +if (!pl330->peripherals[chan_id].slave) + pl330->peripherals[chan_id].slave = slave; +else if (pl330->peripherals[chan_id].slave != slave) { +dev_err (pl330->ddma.dev, +"Can't use same channel with multiple slave devices!\n" ); +return NULL ; + }
This could be nicely split into separate patch.
Best regards,
Krzysztof
Quoted 195 lines
drivers/dma/pl330.c +57
-33+return dma_get_slave_channel (&pl330->peripherals[chan_id].chan); } +static int pl330_add_slave_link (struct pl330_dmac *pl330, +struct dma_pl330_chan *pch) +{ +struct device_link *link; +int i; + +if (pch->slave_link) +return 0 ; + + link =device_link_add (pch->slave, pl330->ddma.dev, +DL_FLAG_PM_RUNTIME |DL_FLAG_RPM_ACTIVE ); +if (!link) +return -ENODEV ; + +for (i =0 ; i < pl330->num_peripherals; i++) +if (pl330->peripherals[i].slave == pch->slave) + pl330->peripherals[i].slave_link = link; +return 0 ; +} + +static void pl330_del_slave_link (struct pl330_dmac *pl330, +struct dma_pl330_chan *pch) +{ +struct device_link *link = pch->slave_link; +int i, count =0 ; + +for (i =0 ; i < pl330->num_peripherals; i++) +if (pl330->peripherals[i].slave == pch->slave && + pl330->peripherals[i].thread) + count++; + +if (count >0 ) +return ; + +device_link_del (link); +for (i =0 ; i < pl330->num_peripherals; i++) +if (pl330->peripherals[i].slave == pch->slave) + pch->slave_link =NULL ; +} +static int pl330_alloc_chan_resources (struct dma_chan *chan) {struct dma_pl330_chan *pch =to_pchan (chan);struct pl330_dmac *pl330 = pch->dmac;unsigned long flags; +int ret =0 ;spin_lock_irqsave (&pch->lock, flags);@@ -2137,6 +2162,14 @@ static int pl330_alloc_chan_resources(struct dma_chan *chan)spin_unlock_irqrestore (&pch->lock, flags); +if (pch->slave) + ret =pl330_add_slave_link (pl330, pch); +else + ret =pm_runtime_get_sync (pl330->ddma.dev); + +if (ret <0 ) +return ret; +return 1 ; }@@ -2171,9 +2204,7 @@ static int pl330_terminate_all(struct dma_chan *chan)unsigned long flags;struct pl330_dmac *pl330 = pch->dmac;LIST_HEAD (list); -bool power_down = false; -pm_runtime_get_sync (pl330->ddma.dev);spin_lock_irqsave (&pch->lock, flags);spin_lock (&pl330->lock);_stop (pch->thread);@@ -2182,8 +2213,6 @@ static int pl330_terminate_all(struct dma_chan *chan) pch->thread->req[0 ].desc =NULL ; pch->thread->req[1 ].desc =NULL ; pch->thread->req_running =-1 ; - power_down = pch->active; - pch->active = false;/* Mark all desc done */ list_for_each_entry (desc, &pch->submitted_list, node) {@@ -2200,10 +2229,6 @@ static int pl330_terminate_all(struct dma_chan *chan)list_splice_tail_init (&pch->work_list, &pl330->desc_pool);list_splice_tail_init (&pch->completed_list, &pl330->desc_pool);spin_unlock_irqrestore (&pch->lock, flags); -pm_runtime_mark_last_busy (pl330->ddma.dev); -if (power_down) -pm_runtime_put_autosuspend (pl330->ddma.dev); -pm_runtime_put_autosuspend (pl330->ddma.dev);return 0 ; }@@ -2221,7 +2246,6 @@ static int pl330_pause(struct dma_chan *chan)struct pl330_dmac *pl330 = pch->dmac;unsigned long flags; -pm_runtime_get_sync (pl330->ddma.dev);spin_lock_irqsave (&pch->lock, flags);spin_lock (&pl330->lock);@@ -2229,8 +2253,6 @@ static int pl330_pause(struct dma_chan *chan)spin_unlock (&pl330->lock);spin_unlock_irqrestore (&pch->lock, flags); -pm_runtime_mark_last_busy (pl330->ddma.dev); -pm_runtime_put_autosuspend (pl330->ddma.dev);return 0 ; }@@ -2238,11 +2260,11 @@ static int pl330_pause(struct dma_chan *chan)static void pl330_free_chan_resources (struct dma_chan *chan) {struct dma_pl330_chan *pch =to_pchan (chan); +struct pl330_dmac *pl330 = pch->dmac;unsigned long flags;tasklet_kill (&pch->task); -pm_runtime_get_sync (pch->dmac->ddma.dev);spin_lock_irqsave (&pch->lock, flags);pl330_release_channel (pch->thread);@@ -2252,19 +2274,20 @@ static void pl330_free_chan_resources(struct dma_chan *chan)list_splice_tail_init (&pch->work_list, &pch->dmac->desc_pool);spin_unlock_irqrestore (&pch->lock, flags); -pm_runtime_mark_last_busy (pch->dmac->ddma.dev); -pm_runtime_put_autosuspend (pch->dmac->ddma.dev); + +if (pch->slave) +pl330_del_slave_link (pl330, pch); +else +pm_runtime_put (pl330->ddma.dev); }static int pl330_get_current_xferred_count (struct dma_pl330_chan *pch,struct dma_pl330_desc *desc) {struct pl330_thread *thrd = pch->thread; -struct pl330_dmac *pl330 = pch->dmac;void __iomem *regs = thrd->dmac->base;u32 val, addr; -pm_runtime_get_sync (pl330->ddma.dev); val = addr =0 ;if (desc->rqcfg.src_inc) { val =readl (regs +SA (thrd->id));@@ -2273,8 +2296,6 @@ static int pl330_get_current_xferred_count(struct dma_pl330_chan *pch, val =readl (regs +DA (thrd->id)); addr = desc->px.dst_addr; } -pm_runtime_mark_last_busy (pch->dmac->ddma.dev); -pm_runtime_put_autosuspend (pl330->ddma.dev);/* If DMAMOV hasn't finished yet, SAR/DAR can be zero */ if (!val)@@ -2360,16 +2381,6 @@ static void pl330_issue_pending(struct dma_chan *chan)unsigned long flags;spin_lock_irqsave (&pch->lock, flags); -if (list_empty (&pch->work_list)) { -/* -* Warn on nothing pending. Empty submitted_list may -* break our pm_runtime usage counter as it is -* updated on work_list emptiness status. -*/ -WARN_ON (list_empty (&pch->submitted_list)); - pch->active = true; -pm_runtime_get_sync (pch->dmac->ddma.dev); - }list_splice_tail_init (&pch->submitted_list, &pch->work_list);spin_unlock_irqrestore (&pch->lock, flags);@@ -2987,11 +2998,7 @@ static int __maybe_unused pl330_resume(struct device *dev) pcfg->data_buf_dep, pcfg->data_bus_width /8 , pcfg->num_chan, pcfg->num_peri, pcfg->num_events); -pm_runtime_irq_safe (&adev->dev); -pm_runtime_use_autosuspend (&adev->dev); -pm_runtime_set_autosuspend_delay (&adev->dev,PL330_AUTOSUSPEND_DELAY ); -pm_runtime_mark_last_busy (&adev->dev); -pm_runtime_put_autosuspend (&adev->dev); +pm_runtime_put (&adev->dev);return 0 ; probe_err3:Signature · 1 line
1.9.1
PATCH 3/3 dmaengine: pl330: Don't require irq-safe runtime PM
Hi Krzysztof,
Quoted 10 lines · Krzysztof Kozlowski
Quoted 9 lines · Marek Szyprowski
This patch replaces irq-safe runtime pm with non-irq-safe version.
Till now non-irq-safe runtime PM implementation was only possible by calling pm_runtime_get/put functions from alloc/free_chan_resources. All other DMA engine API functions cannot be called from a context, which allows sleeping. Such implementation in practice resulted in keeping PL330 DMA controller device active almost all the time, because most of the slave device drivers (DMA engine clients) acquired DMA channel in their
probe()function and released it during driver removal.
Quoted 6 lines
I think that is not accurate (unless something changed recently and I missed it)... The runtime PM in pl330 was infact suspending device when the queue was empty. It was working during the regular work of DMA and slave devices.
Maybe your recent fix changed this?
Please note that the above description was about existing ways of implementing
non-irq-safe runtime pm in a dmaengine driver. PL330 was using irq-safe runtime pm,
which has other issues - the most significant one is keeping clocks prepared all
the time and keeping power domain turned on all the time. Both are real blockers
of taking advantages of the fact that there is a separate power domain for audio
hardware.
Quoted 8 lines
Quoted 1 line
This patch provides a new approach.
Please say why this approach is better because the previous one - was suspending the dma channel when not used. Otherwise, it would make no sense of implement the irq-safe runtime PM at the beginning!
Of course, a change from irq-safe to non-irq-safe is a good reason to implement changes. But that was not mentioned in the first paragraph at all.
The goal of this patchset is to add audio power domain support for Exynos5 SoCs
and let it to be turned off when no sound is being played/recorded. This in turn
requires all devices, which are a part of that power domain to implement runtime
pm support. Maybe I didn't state this strong enough, but I think that there was
such information in the commit message AND cover letter.
Quoted 5 lines
Quoted 2 lines
The main assumption for it is an
observation that there can be only one slave device using each DMA channel.Wait, observation, real requirement or assumption?
Later in the code I see adding such requirement.
Well, observation which result in assumption. I cannot imagine a hardware which
shares slave DMA channel between devices. Also none of the existing platform does it.
Quoted 12 lines
Quoted 4 lines
Using recently introduced device dependencies (links) infrastructure one can ensure proper runtime PM state of PL330 DMA controller. In this approach in
pl330_alloc_chan_resources()function a new dependency is being created between PL330 DMA controller device (as supplier) and given slave deviceQuoted 8 lines
(as consumer). This way PL330 DMA controller device runtime active counter is increased when the slave device is resumed and decreased the same time when given slave device is put to suspend. This way it has been ensured to keep PL330 DMA controller runtime active if there is an active used of any of its DMA channels. Slave device pointer is initially stored in per-channel data in
of_dma_xlatecallback. This is similar to what has been already implemented in Exynos IOMMU driver in commit2f5f44f205cc958b("iommu/exynos: Use device dependency links to control runtime pm").
Quoted 4 lines
Sounds convincing... Interesting approach!
My doubts are:
1. What with more then one slave device? (assumption?)
See above, there are no such cases.
Quoted 2 lines
2. If slave device does not implement runtime PM, then pl330 will be active all the time?
Right, but the goal is to have runtime pm added to all devices in the system.
Quoted 2 lines
3. If slave device implements runtime PM in a way that it's enabled in probe and released in remove, then pl330 will be active all the time?
Then it will force power domain to be turned on all the time and even optional
fine-grained irq-safe runtiem pm in pl330 driver won't help much to reduce power
consumption. I assume that the real goal with runtime pm is to let respective
power domains to be turned off, what gives the best results in terms of power
saving.
Quoted 109 lines
Quoted 7 lines
If one requests memory-to-memory chanel, runtime active counter is increased unconditionally. This might be a drawback of this approach, but PL330 is not really used for memory-to-memory operations due to poor performance in such operations compared to CPU.
Introducing non-irq-safe runtime power management finally allows to turn audio power domain off on Exynos5 SoCs.
... and actually any domain which contained pl330 device so this is nice benefit!
Quoted 99 lines
Removal of irq-safe runtime pm is based on the revert of the following commits:
1. "dmaengine: pl330: fix runtime pm support" commit <no stable id yet>
2. "dmaengine: pl330: Fix hang ondmaengine_terminate_allon certain boards"commit 81cc6edc08705ac0146fe6ac14a0982a31ce6f3d 3. "ARM: 8202/1: dmaengine: pl330: Add runtime Power Management support v12" commit ae43b3289186480f81c78bb63d788a85a3631f47Signed-off-by Marek Szyprowski <[email protected]>--- drivers/dma/pl330.c | 133 +++++++++++++++++++++++++++------------------------- 1 file changed, 70 insertions(+), 63 deletions(-)drivers/dma/pl330.c +6
-30@@ -268,9 +268,6 @@ enum pl330_byteswap {#define NR_DEFAULT_DESC 16 -/* Delay for runtime PM autosuspend, ms */ -#define PL330_AUTOSUSPEND_DELAY 20 -/* Populated by the PL330 core driver for DMA API driver's info */ struct pl330_config {u32 periph_id;@@ -449,7 +446,8 @@ struct dma_pl330_chan {bool cyclic;/* for runtime pm tracking */ -bool active; +struct device *slave; +struct device_link *slave_link; };struct pl330_dmac {@@ -2015,7 +2013,6 @@ static void pl330_tasklet(unsigned long data)struct dma_pl330_chan *pch = (struct dma_pl330_chan *)data;struct dma_pl330_desc *desc, *_dt;unsigned long flags; -bool power_down = false;spin_lock_irqsave (&pch->lock, flags);@@ -2030,18 +2027,10 @@ static void pl330_tasklet(unsigned long data)/* Try to submit a req imm. next to the last completed cookie */ fill_queue (pch); -if (list_empty (&pch->work_list)) { -spin_lock (&pch->thread->dmac->lock); -_stop (pch->thread); -spin_unlock (&pch->thread->dmac->lock); - power_down = true; - pch->active = false; - }else { -/* Make sure the PL330 Channel thread is active */ -spin_lock (&pch->thread->dmac->lock); -_start (pch->thread); -spin_unlock (&pch->thread->dmac->lock); - } +/* Make sure the PL330 Channel thread is active */ +spin_lock (&pch->thread->dmac->lock); +_start (pch->thread); +spin_unlock (&pch->thread->dmac->lock);while (!list_empty (&pch->completed_list)) {struct dmaengine_desc_callback cb;@@ -2054,13 +2043,6 @@ static void pl330_tasklet(unsigned long data)if (pch->cyclic) { desc->status =PREP ;list_move_tail (&desc->node, &pch->work_list); -if (power_down) { - pch->active = true; -spin_lock (&pch->thread->dmac->lock); -_start (pch->thread); -spin_unlock (&pch->thread->dmac->lock); - power_down = false; - } }else { desc->status =FREE ;list_move_tail (&desc->node, &pch->dmac->desc_pool);@@ -2075,12 +2057,6 @@ static void pl330_tasklet(unsigned long data) } }spin_unlock_irqrestore (&pch->lock, flags); - -/* If work list empty, power down */ -if (power_down) { -pm_runtime_mark_last_busy (pch->dmac->ddma.dev); -pm_runtime_put_autosuspend (pch->dmac->ddma.dev); - } }bool pl330_filter (struct dma_chan *chan,void *param)@@ -2113,14 +2089,63 @@ static struct dma_chan *of_dma_pl330_xlate(struct of_phandle_args *dma_spec,if (chan_id >= pl330->num_peripherals)return NULL ;
Quoted 8 lines
drivers/dma/pl330.c static struct dma_chan *of_dma_pl330_xlate(struct of_phandle_args *dma_spec, · line 2098
Quoted 7 lines
drivers/dma/pl330.c +7
-0+if (!pl330->peripherals[chan_id].slave) + pl330->peripherals[chan_id].slave = slave; +else if (pl330->peripherals[chan_id].slave != slave) { +dev_err (pl330->ddma.dev, +"Can't use same channel with multiple slave devices!\n" ); +return NULL ; + }This could be nicely split into separate patch.
Okay, if you want, I can move this change to separate patch.
Quoted 193 lines
Best regards,
KrzysztofQuoted 190 lines
drivers/dma/pl330.c +57
-33+return dma_get_slave_channel (&pl330->peripherals[chan_id].chan); } +static int pl330_add_slave_link (struct pl330_dmac *pl330, +struct dma_pl330_chan *pch) +{ +struct device_link *link; +int i; + +if (pch->slave_link) +return 0 ; + + link =device_link_add (pch->slave, pl330->ddma.dev, +DL_FLAG_PM_RUNTIME |DL_FLAG_RPM_ACTIVE ); +if (!link) +return -ENODEV ; + +for (i =0 ; i < pl330->num_peripherals; i++) +if (pl330->peripherals[i].slave == pch->slave) + pl330->peripherals[i].slave_link = link; +return 0 ; +} + +static void pl330_del_slave_link (struct pl330_dmac *pl330, +struct dma_pl330_chan *pch) +{ +struct device_link *link = pch->slave_link; +int i, count =0 ; + +for (i =0 ; i < pl330->num_peripherals; i++) +if (pl330->peripherals[i].slave == pch->slave && + pl330->peripherals[i].thread) + count++; + +if (count >0 ) +return ; + +device_link_del (link); +for (i =0 ; i < pl330->num_peripherals; i++) +if (pl330->peripherals[i].slave == pch->slave) + pch->slave_link =NULL ; +} +static int pl330_alloc_chan_resources (struct dma_chan *chan) {struct dma_pl330_chan *pch =to_pchan (chan);struct pl330_dmac *pl330 = pch->dmac;unsigned long flags; +int ret =0 ;spin_lock_irqsave (&pch->lock, flags);@@ -2137,6 +2162,14 @@ static int pl330_alloc_chan_resources(struct dma_chan *chan)spin_unlock_irqrestore (&pch->lock, flags); +if (pch->slave) + ret =pl330_add_slave_link (pl330, pch); +else + ret =pm_runtime_get_sync (pl330->ddma.dev); + +if (ret <0 ) +return ret; +return 1 ; }@@ -2171,9 +2204,7 @@ static int pl330_terminate_all(struct dma_chan *chan)unsigned long flags;struct pl330_dmac *pl330 = pch->dmac;LIST_HEAD (list); -bool power_down = false; -pm_runtime_get_sync (pl330->ddma.dev);spin_lock_irqsave (&pch->lock, flags);spin_lock (&pl330->lock);_stop (pch->thread);@@ -2182,8 +2213,6 @@ static int pl330_terminate_all(struct dma_chan *chan) pch->thread->req[0 ].desc =NULL ; pch->thread->req[1 ].desc =NULL ; pch->thread->req_running =-1 ; - power_down = pch->active; - pch->active = false;/* Mark all desc done */ list_for_each_entry (desc, &pch->submitted_list, node) {@@ -2200,10 +2229,6 @@ static int pl330_terminate_all(struct dma_chan *chan)list_splice_tail_init (&pch->work_list, &pl330->desc_pool);list_splice_tail_init (&pch->completed_list, &pl330->desc_pool);spin_unlock_irqrestore (&pch->lock, flags); -pm_runtime_mark_last_busy (pl330->ddma.dev); -if (power_down) -pm_runtime_put_autosuspend (pl330->ddma.dev); -pm_runtime_put_autosuspend (pl330->ddma.dev);return 0 ; }@@ -2221,7 +2246,6 @@ static int pl330_pause(struct dma_chan *chan)struct pl330_dmac *pl330 = pch->dmac;unsigned long flags; -pm_runtime_get_sync (pl330->ddma.dev);spin_lock_irqsave (&pch->lock, flags);spin_lock (&pl330->lock);@@ -2229,8 +2253,6 @@ static int pl330_pause(struct dma_chan *chan)spin_unlock (&pl330->lock);spin_unlock_irqrestore (&pch->lock, flags); -pm_runtime_mark_last_busy (pl330->ddma.dev); -pm_runtime_put_autosuspend (pl330->ddma.dev);return 0 ; }@@ -2238,11 +2260,11 @@ static int pl330_pause(struct dma_chan *chan)static void pl330_free_chan_resources (struct dma_chan *chan) {struct dma_pl330_chan *pch =to_pchan (chan); +struct pl330_dmac *pl330 = pch->dmac;unsigned long flags;tasklet_kill (&pch->task); -pm_runtime_get_sync (pch->dmac->ddma.dev);spin_lock_irqsave (&pch->lock, flags);pl330_release_channel (pch->thread);@@ -2252,19 +2274,20 @@ static void pl330_free_chan_resources(struct dma_chan *chan)list_splice_tail_init (&pch->work_list, &pch->dmac->desc_pool);spin_unlock_irqrestore (&pch->lock, flags); -pm_runtime_mark_last_busy (pch->dmac->ddma.dev); -pm_runtime_put_autosuspend (pch->dmac->ddma.dev); + +if (pch->slave) +pl330_del_slave_link (pl330, pch); +else +pm_runtime_put (pl330->ddma.dev); }static int pl330_get_current_xferred_count (struct dma_pl330_chan *pch,struct dma_pl330_desc *desc) {struct pl330_thread *thrd = pch->thread; -struct pl330_dmac *pl330 = pch->dmac;void __iomem *regs = thrd->dmac->base;u32 val, addr; -pm_runtime_get_sync (pl330->ddma.dev); val = addr =0 ;if (desc->rqcfg.src_inc) { val =readl (regs +SA (thrd->id));@@ -2273,8 +2296,6 @@ static int pl330_get_current_xferred_count(struct dma_pl330_chan *pch, val =readl (regs +DA (thrd->id)); addr = desc->px.dst_addr; } -pm_runtime_mark_last_busy (pch->dmac->ddma.dev); -pm_runtime_put_autosuspend (pl330->ddma.dev);/* If DMAMOV hasn't finished yet, SAR/DAR can be zero */ if (!val)@@ -2360,16 +2381,6 @@ static void pl330_issue_pending(struct dma_chan *chan)unsigned long flags;spin_lock_irqsave (&pch->lock, flags); -if (list_empty (&pch->work_list)) { -/* -* Warn on nothing pending. Empty submitted_list may -* break our pm_runtime usage counter as it is -* updated on work_list emptiness status. -*/ -WARN_ON (list_empty (&pch->submitted_list)); - pch->active = true; -pm_runtime_get_sync (pch->dmac->ddma.dev); - }list_splice_tail_init (&pch->submitted_list, &pch->work_list);spin_unlock_irqrestore (&pch->lock, flags);@@ -2987,11 +2998,7 @@ static int __maybe_unused pl330_resume(struct device *dev) pcfg->data_buf_dep, pcfg->data_bus_width /8 , pcfg->num_chan, pcfg->num_peri, pcfg->num_events); -pm_runtime_irq_safe (&adev->dev); -pm_runtime_use_autosuspend (&adev->dev); -pm_runtime_set_autosuspend_delay (&adev->dev,PL330_AUTOSUSPEND_DELAY ); -pm_runtime_mark_last_busy (&adev->dev); -pm_runtime_put_autosuspend (&adev->dev); +pm_runtime_put (&adev->dev);
Quoted 7 lines
Quoted 5 lines
drivers/dma/pl330.c +0
-0return 0 ; probe_err3:Signature · 1 line
1.9.1
Best regards
Signature · 2 lines
Marek Szyprowski, PhD Samsung R&D Institute Poland
Krzysztof Kozlowski
maintainerPATCH 3/3 dmaengine: pl330: Don't require irq-safe runtime PM
On Fri, Dec 23, 2016 at 11:38:19AM +0100, Marek Szyprowski wrote:
(...)
Quoted 10 lines
Quoted 5 lines
Quoted 2 lines
The main assumption for it is an
observation that there can be only one slave device using each DMA channel.Wait, observation, real requirement or assumption?
Later in the code I see adding such requirement.
Well, observation which result in assumption. I cannot imagine a hardware which
shares slave DMA channel between devices. Also none of the existing platform does it.
OK for me.
Quoted 29 lines
Quoted 13 lines
Quoted 13 lines
Using recently introduced device dependencies (links) infrastructure one can ensure proper runtime PM state of PL330 DMA controller. In this approach in
pl330_alloc_chan_resources()function a new dependency is being created between PL330 DMA controller device (as supplier) and given slave device (as consumer). This way PL330 DMA controller device runtime active counter is increased when the slave device is resumed and decreased the same time when given slave device is put to suspend. This way it has been ensured to keep PL330 DMA controller runtime active if there is an active used of any of its DMA channels. Slave device pointer is initially stored in per-channel data inof_dma_xlatecallback. This is similar to what has been already implemented in Exynos IOMMU driver in commit2f5f44f205cc958b("iommu/exynos: Use device dependency links to control runtime pm").Quoted 4 lines
Sounds convincing... Interesting approach!
My doubts are:
1. What with more then one slave device? (assumption?)See above, there are no such cases.
Quoted 2 lines
2. If slave device does not implement runtime PM, then pl330 will be active all the time?
Right, but the goal is to have runtime pm added to all devices in the system.
Quoted 2 lines
3. If slave device implements runtime PM in a way that it's enabled in probe and released in remove, then pl330 will be active all the time?
Quoted 9 lines
Then it will force power domain to be turned on all the time and even optional
fine-grained irq-safe runtiem pm in pl330 driver won't help much to reduce power
consumption. I assume that the real goal with runtime pm is to let respective
power domains to be turned off, what gives the best results in terms of power
saving.
Indeed existing runtime PM for pl330 was not bringing much benefits of its own - only clocks were enabled/disabled.
Thanks for clarifications.
(...)
Quoted 12 lines
Quoted 11 lines
drivers/dma/pl330.c static struct dma_chan *of_dma_pl330_xlate(struct of_phandle_args *dma_spec, · line 2097
Quoted 10 lines
drivers/dma/pl330.c +7
-0@@ -2113,14 +2089,63 @@ static struct dma_chan *of_dma_pl330_xlate(struct of_phandle_args *dma_spec,if (chan_id >= pl330->num_peripherals)return NULL ; +if (!pl330->peripherals[chan_id].slave) + pl330->peripherals[chan_id].slave = slave; +else if (pl330->peripherals[chan_id].slave != slave) { +dev_err (pl330->ddma.dev, +"Can't use same channel with multiple slave devices!\n" ); +return NULL ; + }This could be nicely split into separate patch.
Quoted 1 line
Okay, if you want, I can move this change to separate patch.
Yes, please do it. Beside that patch looked fine to me.
Best regards,
Krzysztof