linux-dev - Linux kernel development work

Age	Commit message (Collapse)	Author	Files	Lines
2017-12-04	dmaengine: virt-dma: Add helper to free/reuse a descriptor	Peter Ujfalusi	1	-4/+1
	The vchan_vdesc_fini() can be used to free or reuse a given descriptor after it has been marked as completed. Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com> Reviewed-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2017-04-26	dmaengine: virt-dma: Convert to use list_for_each_entry_safe()	Andy Shevchenko	1	-6/+5
	Use list_for_each_entry_safe() instead of open coding variants. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2016-08-08	dmaengine: virt-dma: convert callback to helper function	Dave Jiang	1	-10/+7
	This is in preperation of moving to a callback that provides results to the callback for the transaction. The conversion will maintain current behavior and the driver must convert to new callback mechanism at a later time in order to receive results. Signed-off-by: Dave Jiang <dave.jiang@intel.com> Reviewed-by: Lars-Peter Clausen <lars@metafoo.de> Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2015-11-16	dmaengine: virt-dma: don't always free descriptor upon completion	Robert Jarzmik	1	-6/+40
	This patch attempts to enhance the case of a transfer submitted multiple times, and where the cost of creating the descriptors chain is not negligible. This happens with big video buffers (several megabytes, ie. several thousands of linked descriptors in one scatter-gather list). In these cases, a video driver would want to do : - tx = dmaengine_prep_slave_sg() - dma_engine_submit(tx); - dma_async_issue_pending() - wait for video completion - read video data (or not, skipping a frame is also possible) - dma_engine_submit(tx) => here, the descriptors chain recalculation will take time => the dma coherent allocation over and over might create holes in the dma pool, which is counter-productive. - dma_async_issue_pending() - etc ... In order to cope with this case, virt-dma is modified to prevent freeing the descriptors upon completion if DMA_CTRL_REUSE flag is set in the transfer. This patch is a respin of the former DMA_CTRL_ACK approach, which was reverted due to a regression in audio drivers. Signed-off-by: Robert Jarzmik <robert.jarzmik@free.fr> Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2015-07-31	Revert "dmaengine: virt-dma: don't always free descriptor upon completion"	Jun Nie	1	-13/+6
	This reverts commit b9855f03d560d351e95301b9de0bc3cad3b31fe9. The patch break existing DMA usage case. For example, audio SOC dmaengine never release channel and cause virt-dma to cache too much memory in descriptor to exhaust system memory. Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2015-06-17	dmaengine: virt-dma: don't always free descriptor upon completion	Robert Jarzmik	1	-6/+13
	This patch attempts to enhance the case of a transfer submitted multiple times, and where the cost of creating the descriptors chain is not negligible. This happens with big video buffers (several megabytes, ie. several thousands of linked descriptors in one scatter-gather list). In these cases, a video driver would want to do : - tx = dmaengine_prep_slave_sg() - dma_engine_submit(tx); - dma_async_issue_pending() - wait for video completion - read video data (or not, skipping a frame is also possible) - dma_engine_submit(tx) => here, the descriptors chain recalculation will take time => the dma coherent allocation over and over might create holes in the dma pool, which is counter-productive. - dma_async_issue_pending() - etc ... In order to cope with this case, virt-dma is modified to prevent freeing the descriptors upon completion if DMA_CTRL_ACK flag is set in the transfer. Signed-off-by: Robert Jarzmik <robert.jarzmik@free.fr> Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2012-07-01	dmaengine: virt-dma: add support for cyclic DMA periodic callbacks	Russell King	1	-4/+15
	Add support for cyclic DMA's periodic callbacks. Drivers are expected to call vchan_cyclic_callback() when a period has completed, which will schedule the tasklet to make the callback into the driver. As callbacks are made from tasklet context, it is important to realise that we don't guarantee a callback for each completed period, but for N completed periods where N may be greater than one. Tested-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2012-07-01	dmaengine: virt-dma: vchan_find_desc()	Russell King	1	-0/+13
	Add a function to find a descriptor within the depths of the virtualized DMA channel support. Needed for tx_status functionality. Tested-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2012-07-01	dmaengine: split out virtual channel DMA support from sa11x0 driver	Russell King	1	-0/+99
	Split the virtual slave channel DMA support from the sa11x0 driver so this code can be shared with other slave DMA engine drivers. Acked-by: Linus Walleij <linus.walleij@linaro.org> Tested-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>