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dmaengine: dw-axi_dmac: bug fix clean up and more features

PATCH New Jisheng Zhang 1 participant 12 messages May 21, 2023

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dmaengine Synopsys DesignWare AXI DMAC driver
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Jisheng Zhang

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#0 lore raw

v3 cover dmaengine: dw-axi_dmac: bug fix clean up and more features

This series first fix a bug related with runtime pm. Then do three clean up. After that, we add three new features: per channel irq support, dma-channel-mask support and polled mode support.

Since v3:
- rebase on the latest rc1

Since v2
- fix typo
- add reason why we need to runtime resume before reading reg in commit msg

Hi Vinod,

I still kept patch2 in v2, because I think the irq has been disabled from the dw-axi-dma side, so the irq won't be fired any more. If you prefer to keep the devm_free_irq() just ignore patch2.

Thanks a lot.

Jisheng Zhang (11):
dmaengine: dw-axi-dmac: fix reading register when runtime suspended
dmaengine: dw-axi-dmac: remove unnecessary devm_free_irq() calling
dmaengine: dw-axi-dmac: remove unnecessary axi_dma_enable() calling
dmaengine: dw-axi-dmac: remove redundant axi_dma_disable() calling
dmaengine: dw-axi-dmac: delay irq getting until request_irq
dmaengine: dw-axi-dmac: move ch irq handling into common routine
dmaengine: dw-axi-dmac: support per channel irq
dmaengine: dw-axi-dmac: support dma-channel-mask
dmaengine: dw-axi-dmac: try best to get residue when tx is running
dmaengine: dw-axi-dmac: move dma_chan_tx_status()
dmaengine: dw-axi-dmac: support polled mode

 .../dma/dw-axi-dmac/dw-axi-dmac-platform.c    | 207 ++++++++++++------
 drivers/dma/dw-axi-dmac/dw-axi-dmac.h         |   4 +
 2 files changed, 147 insertions(+), 64 deletions(-)
Signature · 1 line
2.40.0
author
#1 lore raw

PATCH v3 1/11 dmaengine: dw-axi-dmac: fix reading register when runtime suspended

We should runtime resume the device before calling axi_chan_is_hw_enable(), otherwise we may see cpu aborts when accessing registers in axi_chan_is_hw_enable().

Signed-off-by Jisheng Zhang <[email protected]>
---
 drivers/dma/dw-axi-dmac/dw-axi-dmac-platform.c | 15 +++++++++++----
 1 file changed, 11 insertions(+), 4 deletions(-)
drivers/dma/dw-axi-dmac/dw-axi-dmac-platform.c +11 -4
index 796b6caf0bab..203be13499e3 100644
@@ -469,13 +469,17 @@ static void dw_axi_dma_synchronize(struct dma_chan *dchan)
 
 static int dma_chan_alloc_chan_resources(struct dma_chan *dchan)
 {
+	int ret;
 	struct axi_dma_chan *chan = dchan_to_axi_dma_chan(dchan);
 
+	pm_runtime_get(chan->chip->dev);
+
 	/* ASSERT: channel is idle */
 	if (axi_chan_is_hw_enable(chan)) {
 		dev_err(chan2dev(chan), "%s is non-idle!\n",
 			axi_chan_name(chan));
-		return -EBUSY;
+		ret = -EBUSY;
+		goto err_busy;
 	}
 
 	/* LLI address must be aligned to a 64-byte boundary */

@@ -485,13 +489,16 @@ static int dma_chan_alloc_chan_resources(struct dma_chan *dchan)
 					  64, 0);
 	if (!chan->desc_pool) {
 		dev_err(chan2dev(chan), "No memory for descriptors\n");
-		return -ENOMEM;
+		ret = -ENOMEM;
+		goto err_busy;
 	}
 	dev_vdbg(dchan2dev(dchan), "%s: allocating\n", axi_chan_name(chan));
 
-	pm_runtime_get(chan->chip->dev);
-
 	return 0;
+
+err_busy:
+	pm_runtime_put(chan->chip->dev);
+	return ret;
 }
 
 static void dma_chan_free_chan_resources(struct dma_chan *dchan)
Signature · 1 line
2.40.0
author
#2 lore raw

PATCH v3 2/11 dmaengine: dw-axi-dmac: remove unnecessary devm_free_irq() calling

In reply to Jisheng Zhang

In dw_remove(), We have disabled the irq from the dw-axi-dma side, so we are safe against the case "The irq is still ON when devices remove is executed and irq should be quiesced before remove is completed."

Signed-off-by Jisheng Zhang <[email protected]>
---
 drivers/dma/dw-axi-dmac/dw-axi-dmac-platform.c | 2 --
 1 file changed, 2 deletions(-)
drivers/dma/dw-axi-dmac/dw-axi-dmac-platform.c +0 -2
index 203be13499e3..a19b651ddaad 100644
@@ -1563,8 +1563,6 @@ static int dw_remove(struct platform_device *pdev)
 	pm_runtime_disable(chip->dev);
 	axi_dma_suspend(chip);
 
-	devm_free_irq(chip->dev, chip->irq, chip);
-
 	of_dma_controller_free(chip->dev->of_node);
 
 	list_for_each_entry_safe(chan, _chan, &dw->dma.channels,
Signature · 1 line
2.40.0
author
#3 lore raw

PATCH v3 3/11 dmaengine: dw-axi-dmac: remove unnecessary axi_dma_enable() calling

In reply to Jisheng Zhang

The dma is enabled, I.E runtime resumed during chan allocation, and is disable, I.E runtime suspended during chan free. So when starting xfer, we are sure the dma is enabled.

Signed-off-by Jisheng Zhang <[email protected]>
---
 drivers/dma/dw-axi-dmac/dw-axi-dmac-platform.c | 2 --
 1 file changed, 2 deletions(-)
drivers/dma/dw-axi-dmac/dw-axi-dmac-platform.c +0 -2
index a19b651ddaad..4378134eea63 100644
@@ -389,8 +389,6 @@ static void axi_chan_block_xfer_start(struct axi_dma_chan *chan,
 		return;
 	}
 
-	axi_dma_enable(chan->chip);
-
 	config.dst_multblk_type = DWAXIDMAC_MBLK_TYPE_LL;
 	config.src_multblk_type = DWAXIDMAC_MBLK_TYPE_LL;
 	config.tt_fc = DWAXIDMAC_TT_FC_MEM_TO_MEM_DMAC;
Signature · 1 line
2.40.0
author
#4 lore raw

PATCH v3 4/11 dmaengine: dw-axi-dmac: remove redundant axi_dma_disable() calling

In reply to Jisheng Zhang

axi_dma_suspend() will soon call axi_dma_disable(), remove the redundant axi_dma_disable() callin.

Signed-off-by Jisheng Zhang <[email protected]>
---
 drivers/dma/dw-axi-dmac/dw-axi-dmac-platform.c | 1 -
 1 file changed, 1 deletion(-)
drivers/dma/dw-axi-dmac/dw-axi-dmac-platform.c +0 -1
index 4378134eea63..e596910e9f84 100644
@@ -1556,7 +1556,6 @@ static int dw_remove(struct platform_device *pdev)
 		axi_chan_disable(&chip->dw->chan[i]);
 		axi_chan_irq_disable(&chip->dw->chan[i], DWAXIDMAC_IRQ_ALL);
 	}
-	axi_dma_disable(chip);
 
 	pm_runtime_disable(chip->dev);
 	axi_dma_suspend(chip);
Signature · 1 line
2.40.0
author
#5 lore raw

PATCH v3 5/11 dmaengine: dw-axi-dmac: delay irq getting until request_irq

In reply to Jisheng Zhang

This is to prepare for per-channel irq support in next patch. In per-channel irq case, we need to parse dt firstly to know whether the platform is per-channel irq or not.

Signed-off-by Jisheng Zhang <[email protected]>
---
 drivers/dma/dw-axi-dmac/dw-axi-dmac-platform.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)
drivers/dma/dw-axi-dmac/dw-axi-dmac-platform.c +4 -4
index e596910e9f84..64b4ee2d618b 100644
@@ -1403,10 +1403,6 @@ static int dw_probe(struct platform_device *pdev)
 	chip->dev = &pdev->dev;
 	chip->dw->hdata = hdata;
 
-	chip->irq = platform_get_irq(pdev, 0);
-	if (chip->irq < 0)
-		return chip->irq;
-
 	chip->regs = devm_platform_ioremap_resource(pdev, 0);
 	if (IS_ERR(chip->regs))
 		return PTR_ERR(chip->regs);

@@ -1447,6 +1443,10 @@ static int dw_probe(struct platform_device *pdev)
 	if (!dw->chan)
 		return -ENOMEM;
 
+	chip->irq = platform_get_irq(pdev, 0);
+	if (chip->irq < 0)
+		return chip->irq;
+
 	ret = devm_request_irq(chip->dev, chip->irq, dw_axi_dma_interrupt,
 			       IRQF_SHARED, KBUILD_MODNAME, chip);
 	if (ret)
Signature · 1 line
2.40.0
author
#6 lore raw

PATCH v3 6/11 dmaengine: dw-axi-dmac: move ch irq handling into common routine

In reply to Jisheng Zhang

In next patch, we will add per-channel irq support, we will use the common routine in per-channel irq handler.

Signed-off-by Jisheng Zhang <[email protected]>
---
 .../dma/dw-axi-dmac/dw-axi-dmac-platform.c    | 30 ++++++++++++-------
 1 file changed, 19 insertions(+), 11 deletions(-)
drivers/dma/dw-axi-dmac/dw-axi-dmac-platform.c +19 -11
index 64b4ee2d618b..24a93b0c1489 100644
@@ -1108,13 +1108,30 @@ static void axi_chan_block_xfer_complete(struct axi_dma_chan *chan)
 	spin_unlock_irqrestore(&chan->vc.lock, flags);
 }
 
+static void dw_axi_dma_handle_ch(struct axi_dma_chan *chan)
+{
+	u32 status;
+
+	/* Poll, clear and process this channel interrupt status */
+	status = axi_chan_irq_read(chan);
+	axi_chan_irq_clear(chan, status);
+
+	dev_vdbg(chan->chip->dev, "%s IRQ status: 0x%08x\n", axi_chan_name(chan), status);
+
+	if (status & DWAXIDMAC_IRQ_ALL_ERR)
+		axi_chan_handle_err(chan, status);
+	else if (status & DWAXIDMAC_IRQ_DMA_TRF)
+		axi_chan_block_xfer_complete(chan);
+
+}
+
 static irqreturn_t dw_axi_dma_interrupt(int irq, void *dev_id)
 {
 	struct axi_dma_chip *chip = dev_id;
 	struct dw_axi_dma *dw = chip->dw;
 	struct axi_dma_chan *chan;
 
-	u32 status, i;
+	u32 i;
 
 	/* Disable DMAC interrupts. We'll enable them after processing channels */
 	axi_dma_irq_disable(chip);

@@ -1122,16 +1139,7 @@ static irqreturn_t dw_axi_dma_interrupt(int irq, void *dev_id)
 	/* Poll, clear and process every channel interrupt status */
 	for (i = 0; i < dw->hdata->nr_channels; i++) {
 		chan = &dw->chan[i];
-		status = axi_chan_irq_read(chan);
-		axi_chan_irq_clear(chan, status);
-
-		dev_vdbg(chip->dev, "%s %u IRQ status: 0x%08x\n",
-			axi_chan_name(chan), i, status);
-
-		if (status & DWAXIDMAC_IRQ_ALL_ERR)
-			axi_chan_handle_err(chan, status);
-		else if (status & DWAXIDMAC_IRQ_DMA_TRF)
-			axi_chan_block_xfer_complete(chan);
+		dw_axi_dma_handle_ch(chan);
 	}
 
 	/* Re-enable interrupts */
Signature · 1 line
2.40.0
author
#7 lore raw

PATCH v3 7/11 dmaengine: dw-axi-dmac: support per channel irq

In reply to Jisheng Zhang

Each channel can have its own irq, support this case.

Signed-off-by Jisheng Zhang <[email protected]>
---
 .../dma/dw-axi-dmac/dw-axi-dmac-platform.c    | 46 ++++++++++++++++---
 drivers/dma/dw-axi-dmac/dw-axi-dmac.h         |  2 +
 2 files changed, 41 insertions(+), 7 deletions(-)
drivers/dma/dw-axi-dmac/dw-axi-dmac-platform.c +39 -7
index 24a93b0c1489..3f3db48822e3 100644
@@ -1148,6 +1148,21 @@ static irqreturn_t dw_axi_dma_interrupt(int irq, void *dev_id)
 	return IRQ_HANDLED;
 }
 
+static irqreturn_t dw_axi_dma_ch_interrupt(int irq, void *dev_id)
+{
+	struct axi_dma_chan *chan = dev_id;
+
+	/* Disable DMAC interrupts. We'll enable them after processing channels */
+	axi_chan_irq_sig_set(chan, DWAXIDMAC_IRQ_NONE);
+
+	dw_axi_dma_handle_ch(chan);
+
+	/* Re-enable interrupts */
+	axi_chan_irq_sig_set(chan, DWAXIDMAC_IRQ_DMA_TRF | DWAXIDMAC_IRQ_ALL_ERR);
+
+	return IRQ_HANDLED;
+}
+
 static int dma_chan_terminate_all(struct dma_chan *dchan)
 {
 	struct axi_dma_chan *chan = dchan_to_axi_dma_chan(dchan);

@@ -1382,6 +1397,8 @@ static int parse_device_properties(struct axi_dma_chip *chip)
 		chip->dw->hdata->axi_rw_burst_len = tmp;
 	}
 
+	chip->dw->hdata->perch_irq = device_property_read_bool(dev, "snps,perch_irq");
+
 	return 0;
 }
 

@@ -1451,14 +1468,29 @@ static int dw_probe(struct platform_device *pdev)
 	if (!dw->chan)
 		return -ENOMEM;
 
-	chip->irq = platform_get_irq(pdev, 0);
-	if (chip->irq < 0)
-		return chip->irq;
+	if (hdata->perch_irq) {
+		char irqname[8];
+		for (i = 0; i < hdata->nr_channels; i++) {
+			snprintf(irqname, sizeof(irqname), "ch%u", i);
+			dw->chan[i].irq = platform_get_irq_byname(pdev, irqname);
+			if (dw->chan[i].irq < 0)
+				return dw->chan[i].irq;
+			ret = devm_request_irq(chip->dev, dw->chan[i].irq,
+					       dw_axi_dma_ch_interrupt,
+					       0, KBUILD_MODNAME, &dw->chan[i]);
+			if (ret)
+				return ret;
+		}
+	} else {
+		chip->irq = platform_get_irq(pdev, 0);
+		if (chip->irq < 0)
+			return chip->irq;
 
-	ret = devm_request_irq(chip->dev, chip->irq, dw_axi_dma_interrupt,
-			       IRQF_SHARED, KBUILD_MODNAME, chip);
-	if (ret)
-		return ret;
+		ret = devm_request_irq(chip->dev, chip->irq, dw_axi_dma_interrupt,
+				       IRQF_SHARED, KBUILD_MODNAME, chip);
+		if (ret)
+			return ret;
+	}
 
 	INIT_LIST_HEAD(&dw->dma.channels);
 	for (i = 0; i < hdata->nr_channels; i++) {
drivers/dma/dw-axi-dmac/dw-axi-dmac.h +2 -0
index eb267cb24f67..49210a248c27 100644
@@ -34,6 +34,7 @@ struct dw_axi_dma_hcfg {
 	bool	reg_map_8_channels;
 	bool	restrict_axi_burst_len;
 	bool	use_cfg2;
+	bool	perch_irq;
 };
 
 struct axi_dma_chan {

@@ -49,6 +50,7 @@ struct axi_dma_chan {
 	struct axi_dma_desc		*desc;
 	struct dma_slave_config		config;
 	enum dma_transfer_direction	direction;
+	int				irq;
 	bool				cyclic;
 	/* these other elements are all protected by vc.lock */
 	bool				is_paused;
Signature · 1 line
2.40.0
author
#8 lore raw

PATCH v3 8/11 dmaengine: dw-axi-dmac: support dma-channel-mask

In reply to Jisheng Zhang

Some dma channels may not be available, so we need to tell the driver the available dma channels, use the general dt binding "dma-channel-mask" for this purpose.

Signed-off-by Jisheng Zhang <[email protected]>
---
 .../dma/dw-axi-dmac/dw-axi-dmac-platform.c    | 19 +++++++++++++++++++
 drivers/dma/dw-axi-dmac/dw-axi-dmac.h         |  1 +
 2 files changed, 20 insertions(+)
drivers/dma/dw-axi-dmac/dw-axi-dmac-platform.c +19 -0
index 3f3db48822e3..f0bd8a7e3caf 100644
@@ -223,6 +223,8 @@ static void axi_dma_hw_init(struct axi_dma_chip *chip)
 	u32 i;
 
 	for (i = 0; i < chip->dw->hdata->nr_channels; i++) {
+		if (!(chip->dw->hdata->channels_mask & (1 << i)))
+			continue;
 		axi_chan_irq_disable(&chip->dw->chan[i], DWAXIDMAC_IRQ_ALL);
 		axi_chan_disable(&chip->dw->chan[i]);
 	}

@@ -1397,6 +1399,14 @@ static int parse_device_properties(struct axi_dma_chip *chip)
 		chip->dw->hdata->axi_rw_burst_len = tmp;
 	}
 
+	/*
+	 * Use all channels if there's no dma-channel-mask property
+	 */
+	ret = device_property_read_u32(dev, "dma-channel-mask", &tmp);
+	if (ret)
+		tmp = GENMASK(chip->dw->hdata->nr_channels - 1, 0);
+	chip->dw->hdata->channels_mask = tmp;
+
 	chip->dw->hdata->perch_irq = device_property_read_bool(dev, "snps,perch_irq");
 
 	return 0;

@@ -1471,6 +1481,10 @@ static int dw_probe(struct platform_device *pdev)
 	if (hdata->perch_irq) {
 		char irqname[8];
 		for (i = 0; i < hdata->nr_channels; i++) {
+			if (!(hdata->channels_mask & (1 << i))) {
+				dw->chan[i].irq = -1;
+				continue;
+			}
 			snprintf(irqname, sizeof(irqname), "ch%u", i);
 			dw->chan[i].irq = platform_get_irq_byname(pdev, irqname);
 			if (dw->chan[i].irq < 0)

@@ -1496,6 +1510,9 @@ static int dw_probe(struct platform_device *pdev)
 	for (i = 0; i < hdata->nr_channels; i++) {
 		struct axi_dma_chan *chan = &dw->chan[i];
 
+		if (!(hdata->channels_mask & (1 << i)))
+			continue;
+
 		chan->chip = chip;
 		chan->id = i;
 		chan->chan_regs = chip->regs + COMMON_REG_LEN + i * CHAN_REG_LEN;

@@ -1593,6 +1610,8 @@ static int dw_remove(struct platform_device *pdev)
 	clk_prepare_enable(chip->core_clk);
 	axi_dma_irq_disable(chip);
 	for (i = 0; i < dw->hdata->nr_channels; i++) {
+		if (!(dw->hdata->channels_mask & (1 << i)))
+			continue;
 		axi_chan_disable(&chip->dw->chan[i]);
 		axi_chan_irq_disable(&chip->dw->chan[i], DWAXIDMAC_IRQ_ALL);
 	}
drivers/dma/dw-axi-dmac/dw-axi-dmac.h +1 -0
index 49210a248c27..1f9772e9be30 100644
@@ -30,6 +30,7 @@ struct dw_axi_dma_hcfg {
 	u32	priority[DMAC_MAX_CHANNELS];
 	/* maximum supported axi burst length */
 	u32	axi_rw_burst_len;
+	u32	channels_mask;
 	/* Register map for DMAX_NUM_CHANNELS <= 8 */
 	bool	reg_map_8_channels;
 	bool	restrict_axi_burst_len;
Signature · 1 line
2.40.0
author
#9 lore raw

PATCH v3 9/11 dmaengine: dw-axi-dmac: try best to get residue when tx is running

In reply to Jisheng Zhang

When tx is running, vchan_find_desc() will return NULL, try our best to get the residue in this case.

Signed-off-by Jisheng Zhang <[email protected]>
---
 drivers/dma/dw-axi-dmac/dw-axi-dmac-platform.c | 15 ++++++++++++---
 1 file changed, 12 insertions(+), 3 deletions(-)
drivers/dma/dw-axi-dmac/dw-axi-dmac-platform.c +12 -3
index f0bd8a7e3caf..f14fdfc9c7e9 100644
@@ -312,6 +312,7 @@ dma_chan_tx_status(struct dma_chan *dchan, dma_cookie_t cookie,
 		  struct dma_tx_state *txstate)
 {
 	struct axi_dma_chan *chan = dchan_to_axi_dma_chan(dchan);
+	struct axi_dma_desc *desc = NULL;
 	struct virt_dma_desc *vdesc;
 	enum dma_status status;
 	u32 completed_length;

@@ -329,9 +330,15 @@ dma_chan_tx_status(struct dma_chan *dchan, dma_cookie_t cookie,
 
 	vdesc = vchan_find_desc(&chan->vc, cookie);
 	if (vdesc) {
-		length = vd_to_axi_desc(vdesc)->length;
-		completed_blocks = vd_to_axi_desc(vdesc)->completed_blocks;
-		len = vd_to_axi_desc(vdesc)->hw_desc[0].len;
+		desc = vd_to_axi_desc(vdesc);
+	} else if (chan->desc && chan->desc->vd.tx.cookie == cookie) {
+		desc = chan->desc;
+	}
+
+	if (desc) {
+		length = desc->length;
+		completed_blocks = desc->completed_blocks;
+		len = desc->hw_desc[0].len;
 		completed_length = completed_blocks * len;
 		bytes = length - completed_length;
 	}

@@ -432,6 +439,7 @@ static void axi_chan_block_xfer_start(struct axi_dma_chan *chan,
 	axi_chan_irq_set(chan, irq_mask);
 
 	axi_chan_enable(chan);
+	chan->desc = first;
 }
 
 static void axi_chan_start_first_queued(struct axi_dma_chan *chan)

@@ -1195,6 +1203,7 @@ static int dma_chan_terminate_all(struct dma_chan *dchan)
 	spin_unlock_irqrestore(&chan->vc.lock, flags);
 
 	vchan_dma_desc_free_list(&chan->vc, &head);
+	chan->desc = NULL;
 
 	dev_vdbg(dchan2dev(dchan), "terminated: %s\n", axi_chan_name(chan));
Signature · 1 line
2.40.0
author
#10 lore raw

PATCH v3 10/11 dmaengine: dw-axi-dmac: move dma_chan_tx_status()

In reply to Jisheng Zhang

We will add polled support soon, for which we need to call dw_axi_dma_handle_ch() in dma_chan_tx_status(). Move the function to avoid pre-declaration.

No functionality changes.

Signed-off-by Jisheng Zhang <[email protected]>
---
 .../dma/dw-axi-dmac/dw-axi-dmac-platform.c    | 84 +++++++++----------
 1 file changed, 42 insertions(+), 42 deletions(-)
drivers/dma/dw-axi-dmac/dw-axi-dmac-platform.c +42 -42
index f14fdfc9c7e9..091c15c2ec31 100644
@@ -307,48 +307,6 @@ static void vchan_desc_put(struct virt_dma_desc *vdesc)
 	axi_desc_put(vd_to_axi_desc(vdesc));
 }
 
-static enum dma_status
-dma_chan_tx_status(struct dma_chan *dchan, dma_cookie_t cookie,
-		  struct dma_tx_state *txstate)
-{
-	struct axi_dma_chan *chan = dchan_to_axi_dma_chan(dchan);
-	struct axi_dma_desc *desc = NULL;
-	struct virt_dma_desc *vdesc;
-	enum dma_status status;
-	u32 completed_length;
-	unsigned long flags;
-	u32 completed_blocks;
-	size_t bytes = 0;
-	u32 length;
-	u32 len;
-
-	status = dma_cookie_status(dchan, cookie, txstate);
-	if (status == DMA_COMPLETE || !txstate)
-		return status;
-
-	spin_lock_irqsave(&chan->vc.lock, flags);
-
-	vdesc = vchan_find_desc(&chan->vc, cookie);
-	if (vdesc) {
-		desc = vd_to_axi_desc(vdesc);
-	} else if (chan->desc && chan->desc->vd.tx.cookie == cookie) {
-		desc = chan->desc;
-	}
-
-	if (desc) {
-		length = desc->length;
-		completed_blocks = desc->completed_blocks;
-		len = desc->hw_desc[0].len;
-		completed_length = completed_blocks * len;
-		bytes = length - completed_length;
-	}
-
-	spin_unlock_irqrestore(&chan->vc.lock, flags);
-	dma_set_residue(txstate, bytes);
-
-	return status;
-}
-
 static void write_desc_llp(struct axi_dma_hw_desc *desc, dma_addr_t adr)
 {
 	desc->lli->llp = cpu_to_le64(adr);

@@ -1173,6 +1131,48 @@ static irqreturn_t dw_axi_dma_ch_interrupt(int irq, void *dev_id)
 	return IRQ_HANDLED;
 }
 
+static enum dma_status
+dma_chan_tx_status(struct dma_chan *dchan, dma_cookie_t cookie,
+		  struct dma_tx_state *txstate)
+{
+	struct axi_dma_chan *chan = dchan_to_axi_dma_chan(dchan);
+	struct axi_dma_desc *desc = NULL;
+	struct virt_dma_desc *vdesc;
+	enum dma_status status;
+	u32 completed_length;
+	unsigned long flags;
+	u32 completed_blocks;
+	size_t bytes = 0;
+	u32 length;
+	u32 len;
+
+	status = dma_cookie_status(dchan, cookie, txstate);
+	if (status == DMA_COMPLETE || !txstate)
+		return status;
+
+	spin_lock_irqsave(&chan->vc.lock, flags);
+
+	vdesc = vchan_find_desc(&chan->vc, cookie);
+	if (vdesc) {
+		desc = vd_to_axi_desc(vdesc);
+	} else if (chan->desc && chan->desc->vd.tx.cookie == cookie) {
+		desc = chan->desc;
+	}
+
+	if (desc) {
+		length = desc->length;
+		completed_blocks = desc->completed_blocks;
+		len = desc->hw_desc[0].len;
+		completed_length = completed_blocks * len;
+		bytes = length - completed_length;
+	}
+
+	spin_unlock_irqrestore(&chan->vc.lock, flags);
+	dma_set_residue(txstate, bytes);
+
+	return status;
+}
+
 static int dma_chan_terminate_all(struct dma_chan *dchan)
 {
 	struct axi_dma_chan *chan = dchan_to_axi_dma_chan(dchan);
Signature · 1 line
2.40.0
author
#11 lore raw

PATCH v3 11/11 dmaengine: dw-axi-dmac: support polled mode

In reply to Jisheng Zhang

Run in polled mode if the DMA_PREP_INTERRUPT flag is not provided.

Signed-off-by Jisheng Zhang <[email protected]>
---
 drivers/dma/dw-axi-dmac/dw-axi-dmac-platform.c | 11 ++++++++++-
 drivers/dma/dw-axi-dmac/dw-axi-dmac.h          |  1 +
 2 files changed, 11 insertions(+), 1 deletion(-)
drivers/dma/dw-axi-dmac/dw-axi-dmac-platform.c +10 -1
index 091c15c2ec31..37ab9a03d94b 100644
@@ -390,7 +390,10 @@ static void axi_chan_block_xfer_start(struct axi_dma_chan *chan,
 	write_chan_llp(chan, first->hw_desc[0].llp | lms);
 
 	irq_mask = DWAXIDMAC_IRQ_DMA_TRF | DWAXIDMAC_IRQ_ALL_ERR;
-	axi_chan_irq_sig_set(chan, irq_mask);
+	if (chan->polled)
+		axi_chan_irq_sig_set(chan, DWAXIDMAC_IRQ_NONE);
+	else
+		axi_chan_irq_sig_set(chan, irq_mask);
 
 	/* Generate 'suspend' status but don't generate interrupt */
 	irq_mask |= DWAXIDMAC_IRQ_SUSPENDED;

@@ -721,6 +724,7 @@ dw_axi_dma_chan_prep_cyclic(struct dma_chan *dchan, dma_addr_t dma_addr,
 	if (unlikely(!desc))
 		goto err_desc_get;
 
+	chan->polled = !(flags & DMA_PREP_INTERRUPT);
 	chan->direction = direction;
 	desc->chan = chan;
 	chan->cyclic = true;

@@ -803,6 +807,7 @@ dw_axi_dma_chan_prep_slave_sg(struct dma_chan *dchan, struct scatterlist *sgl,
 
 	desc->chan = chan;
 	desc->length = 0;
+	chan->polled = !(flags & DMA_PREP_INTERRUPT);
 	chan->direction = direction;
 
 	for_each_sg(sgl, sg, sg_len, i) {

@@ -866,6 +871,7 @@ dma_chan_prep_dma_memcpy(struct dma_chan *dchan, dma_addr_t dst_adr,
 	if (unlikely(!desc))
 		goto err_desc_get;
 
+	chan->polled = !(flags & DMA_PREP_INTERRUPT);
 	desc->chan = chan;
 	num = 0;
 	desc->length = 0;

@@ -1146,6 +1152,9 @@ dma_chan_tx_status(struct dma_chan *dchan, dma_cookie_t cookie,
 	u32 length;
 	u32 len;
 
+	if (chan->polled)
+		dw_axi_dma_handle_ch(chan);
+
 	status = dma_cookie_status(dchan, cookie, txstate);
 	if (status == DMA_COMPLETE || !txstate)
 		return status;
drivers/dma/dw-axi-dmac/dw-axi-dmac.h +1 -0
index 1f9772e9be30..33ae4280dacc 100644
@@ -55,6 +55,7 @@ struct axi_dma_chan {
 	bool				cyclic;
 	/* these other elements are all protected by vc.lock */
 	bool				is_paused;
+	bool				polled;
 };
 
 struct dw_axi_dma {
Signature · 1 line
2.40.0