Hi Kedar, On Monday 19 Dec 2016 15:39:43 Appana Durga Kedareswara Rao wrote: > Hi Laurent Pinchart, > > Thanks for the review... > > > > + if (!chan->idle) > > > + return; > > > > Don't you need to perform the same check for the DMA and CDMA channels ? > > If so, shouldn't this be moved to common code ? > > Will fix it in v2... > > > There's another problem (not strictly introduced by this patch) I wanted > > to mention. The append_desc_queue() function, called from your tx_submit > > handler, appends descriptors to the pending_list. The DMA engine API > > states that a transfer submitted by tx_submit will not be executed until > > .issue_pending() is called. However, if a transfer is in progress at > > tx_submit time, I believe that the IRQ handler, at transfer completion, > > will start the next transfer from the pending_list even if > > .issue_pending() hasn't been called for it. > > > > > if (list_empty(&chan->pending_list)) > > > return; > > If user submits more than h/w limit then that case only driver will process > The descriptors from the pending_list for other cases the pending_list will > be Empty so driver just returns from there. I understand that, but that's not the problem. Your .tx_submit() handler calls append_desc_queue() which adds the tx descriptor to the pending_list. If a transfer is in progress at that time, I believe the transfer completion IRQ handler will take the next descriptor from the pending_list and process it, even though issue_pending() hasn't been called for it. > > Now that you catch busy channels with a software flag, do you still need > > the xilinx_dma_is_running() and xilinx_dma_is_idle() checks ? Three > > different checks for the same or very similar conditions are confusing, > > if you really need them you should document clearly how they differ. > > Will remove the xilinx_dma_is_running and xilinx_dmais_idle() checks and > will use Chan->idle check across all the IP's. Will fix it v2... > > > > @@ -1110,6 +1116,7 @@ static void xilinx_vdma_start_transfer(struct > > > xilinx_dma_chan *chan) vdma_desc_write(chan, XILINX_DMA_REG_VSIZE, > > > last->hw.vsize); > > > > > > } > > > > > > + chan->idle = false; > > > > (and this too) > > Will fix in v2... -- Regards, Laurent Pinchart -- To unsubscribe from this list: send the line "unsubscribe dmaengine" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
