On 6 September 2011 17:57, Russell King - ARM Linux <linux@xxxxxxxxxxxxxxxx> wrote: > On Tue, Sep 06, 2011 at 05:52:19PM +0530, Jassi Brar wrote: >> On Fri, Sep 2, 2011 at 6:14 AM, Boojin Kim <boojin.kim@xxxxxxxxxxx> wrote: >> > Origianl code carries out the start operation after flush operation. >> > But start operation is not required for DMA_TERMINATE_ALL command. >> > So, This patch removes the unnecessary start operation and only carries out >> > the flush oeration for handling DMA_TERMINATE_ALL command. >> >> Not exactly. The 'start' is impotent when called from this path because there >> is nothing left queued after the call to 'flush'. >> pl330_tasklet() is called because that is a common function that does the >> house-keeping acc to what's presently in 'work' and 'done' lists. >> >> Though as a side-effect, your patch does avoid doing callbacks on submitted >> xfers during DMA_TERMINATE_ALL - which may or may not be the right thing >> to do. > > It is defined that DMA_TERMINATE_ALL does not call the callbacks: > > 1. int dmaengine_terminate_all(struct dma_chan *chan) > > This causes all activity for the DMA channel to be stopped, and may > discard data in the DMA FIFO which hasn't been fully transferred. > No callback functions will be called for any incomplete transfers. > Ok, thanks for the info. Boojin Kim, please re-write the changelog to state only preventing callbacks during DMA_TERMINATE_ALL as the reason. -- To unsubscribe from this list: send the line "unsubscribe linux-samsung-soc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
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