| Message ID | 20220117091740.11064-1-amelie.delaunay@foss.st.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | dmaengine: stm32-dma: set dma_device max_sg_burst | expand |
Hi, thanks Amelie. Tested-by: Alain Volmat <alain.volmat@foss.st.com> Alain On Mon, Jan 17, 2022 at 10:17:40AM +0100, Amelie Delaunay wrote: > Some stm32-dma consumers [1] rather use dma_get_slave_caps() to get > max_sg_burst of their DMA channel as dma_get_max_seg_size() is specific to > the DMA controller. > All stm32-dma channels have the same features so, don't need to implement > device_caps ops. Let dma_get_slave_caps() relies on dma_device > configuration. > That's why this patch sets dma_device max_sg_burst to the maximum segment > size, which is the maximum of data items that can be transferred without > software intervention. > > [1] https://lore.kernel.org/lkml/20220110103739.118426-1-alain.volmat@foss.st.com/ > "media: stm32: dcmi: create a dma scatterlist based on DMA max_sg_burst value" > > Signed-off-by: Amelie Delaunay <amelie.delaunay@foss.st.com> > --- > drivers/dma/stm32-dma.c | 1 + > 1 file changed, 1 insertion(+) > > diff --git a/drivers/dma/stm32-dma.c b/drivers/dma/stm32-dma.c > index 83a37a6955a3..d2365fab1b7a 100644 > --- a/drivers/dma/stm32-dma.c > +++ b/drivers/dma/stm32-dma.c > @@ -1389,6 +1389,7 @@ static int stm32_dma_probe(struct platform_device *pdev) > dd->residue_granularity = DMA_RESIDUE_GRANULARITY_BURST; > dd->copy_align = DMAENGINE_ALIGN_32_BYTES; > dd->max_burst = STM32_DMA_MAX_BURST; > + dd->max_sg_burst = STM32_DMA_ALIGNED_MAX_DATA_ITEMS; > dd->descriptor_reuse = true; > dd->dev = &pdev->dev; > INIT_LIST_HEAD(&dd->channels); > -- > 2.25.1 >
On 17-01-22, 10:17, Amelie Delaunay wrote: > Some stm32-dma consumers [1] rather use dma_get_slave_caps() to get > max_sg_burst of their DMA channel as dma_get_max_seg_size() is specific to > the DMA controller. > All stm32-dma channels have the same features so, don't need to implement > device_caps ops. Let dma_get_slave_caps() relies on dma_device > configuration. > That's why this patch sets dma_device max_sg_burst to the maximum segment > size, which is the maximum of data items that can be transferred without > software intervention. Applied, thanks
diff --git a/drivers/dma/stm32-dma.c b/drivers/dma/stm32-dma.c index 83a37a6955a3..d2365fab1b7a 100644 --- a/drivers/dma/stm32-dma.c +++ b/drivers/dma/stm32-dma.c @@ -1389,6 +1389,7 @@ static int stm32_dma_probe(struct platform_device *pdev) dd->residue_granularity = DMA_RESIDUE_GRANULARITY_BURST; dd->copy_align = DMAENGINE_ALIGN_32_BYTES; dd->max_burst = STM32_DMA_MAX_BURST; + dd->max_sg_burst = STM32_DMA_ALIGNED_MAX_DATA_ITEMS; dd->descriptor_reuse = true; dd->dev = &pdev->dev; INIT_LIST_HEAD(&dd->channels);
Some stm32-dma consumers [1] rather use dma_get_slave_caps() to get max_sg_burst of their DMA channel as dma_get_max_seg_size() is specific to the DMA controller. All stm32-dma channels have the same features so, don't need to implement device_caps ops. Let dma_get_slave_caps() relies on dma_device configuration. That's why this patch sets dma_device max_sg_burst to the maximum segment size, which is the maximum of data items that can be transferred without software intervention. [1] https://lore.kernel.org/lkml/20220110103739.118426-1-alain.volmat@foss.st.com/ "media: stm32: dcmi: create a dma scatterlist based on DMA max_sg_burst value" Signed-off-by: Amelie Delaunay <amelie.delaunay@foss.st.com> --- drivers/dma/stm32-dma.c | 1 + 1 file changed, 1 insertion(+)