spi: dw: fix multiple slaves with different baudrates
PATCH 1/2 spi: dw: fix multiple slaves with different baudrates
Add current master clock to dws struct and compare it against the requestedtransfer speed. Update clock divider only if necessary.
---
The current implementation stores the transfer speed in the chip struct. If there are multiple slaves which need different clock speeds, the clk_div only gets updated the first time for each slave as speed_hz is 0. After that the comparison always shows the transfer-speed to be equal to the chipspeed and the divider is not updated.
--- drivers/spi/spi-dw.c | 15 +++++++-------- drivers/spi/spi-dw.h | 1 + 2 files changed, 8 insertions(+), 8 deletions(-)
drivers/spi/spi-dw.c +7 -8
@@ -283,7 +283,6 @@ static int dw_spi_transfer_one(struct spi_master *master,struct chip_data *chip =spi_get_ctldata (spi);u8 imask =0 ;u16 txlevel =0 ; -u16 clk_div;u32 cr0;int ret;
@@ -298,13 +297,13 @@ static int dw_spi_transfer_one(struct spi_master *master,spi_enable_chip (dws,0 );/* Handle per transfer options for bpw and speed */ -if (transfer->speed_hz != chip->speed_hz) { -/* clk_div doesn't support odd number */ - clk_div = (dws->max_freq / transfer->speed_hz +1 ) &0xfffe ; - - chip->speed_hz = transfer->speed_hz; - chip->clk_div = clk_div; - +if (transfer->speed_hz != dws->current_freq) { +if (transfer->speed_hz != chip->speed_hz) { +/* clk_div doesn't support odd number */ + chip->clk_div = (dws->max_freq / transfer->speed_hz +1 ) &0xfffe ; + chip->speed_hz = transfer->speed_hz; + } + dws->current_freq = transfer->speed_hz;spi_set_clk (dws, chip->clk_div); }if (transfer->bits_per_word ==8 ) {
drivers/spi/spi-dw.h +1 -0
@@ -123,6 +123,7 @@ struct dw_spi {u8 n_bytes;/* current is a 1/2 bytes op */ u32 dma_width;irqreturn_t (*transfer_handler)(struct dw_spi *dws); +u32 current_freq;/* frequency in hz */ /* DMA info */ int dma_inited;
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Quoted 2 lines · Matthias Seidel
Add current master clock to dws struct and compare it against the requestedtransfer speed. Update clock divider only if necessary.
This doesn't apply against current code, please check and resend.
A message that is not in the archive (sent off-list or not yet received): [email protected]
PATCH v2 1/2 spi: dw: fix multiple slaves with different baudrates
Add current master clock to dws struct and compare it against the requestedtransfer speed. Update clock divider only if necessary.
---
v2 First time for me, Thunderbird messed up the tabs, sorry.
---
The current implementation stores the transfer speed in the chip struct. If there are multiple slaves which need different clock speeds, the clk_div only gets updated the first time for each slave as speed_hz is 0. After that the comparison always shows the transfer-speed to be equal to the chipspeed and the divider is not updated.
--- drivers/spi/spi-dw.c | 15 +++++++-------- drivers/spi/spi-dw.h | 1 + 2 files changed, 8 insertions(+), 8 deletions(-)
drivers/spi/spi-dw.c +7 -8
@@ -283,7 +283,6 @@ static int dw_spi_transfer_one(struct spi_master *master,struct chip_data *chip =spi_get_ctldata (spi);u8 imask =0 ;u16 txlevel =0 ; -u16 clk_div;u32 cr0;int ret;
@@ -298,13 +297,13 @@ static int dw_spi_transfer_one(struct spi_master *master,spi_enable_chip (dws,0 );/* Handle per transfer options for bpw and speed */ -if (transfer->speed_hz != chip->speed_hz) { -/* clk_div doesn't support odd number */ - clk_div = (dws->max_freq / transfer->speed_hz +1 ) &0xfffe ; - - chip->speed_hz = transfer->speed_hz; - chip->clk_div = clk_div; - +if (transfer->speed_hz != dws->current_freq) { +if (transfer->speed_hz != chip->speed_hz) { +/* clk_div doesn't support odd number */ + chip->clk_div = (dws->max_freq / transfer->speed_hz +1 ) &0xfffe ; + chip->speed_hz = transfer->speed_hz; + } + dws->current_freq = transfer->speed_hz;spi_set_clk (dws, chip->clk_div); }if (transfer->bits_per_word ==8 ) {
drivers/spi/spi-dw.h +1 -0
@@ -123,6 +123,7 @@ struct dw_spi {u8 n_bytes;/* current is a 1/2 bytes op */ u32 dma_width;irqreturn_t (*transfer_handler)(struct dw_spi *dws); +u32 current_freq;/* frequency in hz */ /* DMA info */ int dma_inited;
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Applied "spi: dw: fix multiple slaves with different baudrates" to the spi tree
The patch
spi: dw: fix multiple slaves with different baudrates
has been applied to the spi tree at
git://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi.git
All being well this means that it will be integrated into the linux-next tree (usually sometime in the next 24 hours) and sent to Linus during the next merge window (or sooner if it is a bug fix), however if problems are discovered then the patch may be dropped or reverted.
You may get further e-mails resulting from automated or manual testing and review of the tree, please engage with people reporting problems and send followup patches addressing any issues that are reported if needed.
If any updates are required or you are submitting further changes they should be sent as incremental updates against current git, existing patches will not be replaced.
Please add any relevant lists and maintainers to the CCs when replying to this mail.
Thanks,
Mark
Quoted 1 line
From
13b10301b858e355613bfc6dc297580bf34d3fb5Mon Sep 17 00:00:00 2001
From: Matthias Seidel <[email protected]>
Date: Sun, 4 Sep 2016 02:04:49 +0200
Subject: [PATCH] spi: dw: fix multiple slaves with different baudrates
Add current master clock to dws struct and compare it against the requestedtransfer speed. Update clock divider only if necessary.
--- drivers/spi/spi-dw.c | 15 +++++++-------- drivers/spi/spi-dw.h | 1 + 2 files changed, 8 insertions(+), 8 deletions(-)
drivers/spi/spi-dw.c +7 -8
@@ -283,7 +283,6 @@ static int dw_spi_transfer_one(struct spi_master *master,struct chip_data *chip =spi_get_ctldata (spi);u8 imask =0 ;u16 txlevel =0 ; -u16 clk_div;u32 cr0;int ret;
@@ -298,13 +297,13 @@ static int dw_spi_transfer_one(struct spi_master *master,spi_enable_chip (dws,0 );/* Handle per transfer options for bpw and speed */ -if (transfer->speed_hz != chip->speed_hz) { -/* clk_div doesn't support odd number */ - clk_div = (dws->max_freq / transfer->speed_hz +1 ) &0xfffe ; - - chip->speed_hz = transfer->speed_hz; - chip->clk_div = clk_div; - +if (transfer->speed_hz != dws->current_freq) { +if (transfer->speed_hz != chip->speed_hz) { +/* clk_div doesn't support odd number */ + chip->clk_div = (dws->max_freq / transfer->speed_hz +1 ) &0xfffe ; + chip->speed_hz = transfer->speed_hz; + } + dws->current_freq = transfer->speed_hz;spi_set_clk (dws, chip->clk_div); }if (transfer->bits_per_word ==8 ) {
drivers/spi/spi-dw.h +1 -0
@@ -123,6 +123,7 @@ struct dw_spi {u8 n_bytes;/* current is a 1/2 bytes op */ u32 dma_width;irqreturn_t (*transfer_handler)(struct dw_spi *dws); +u32 current_freq;/* frequency in hz */ /* DMA info */ int dma_inited;
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