Commit 4fbf41ce authored by Laurent Pinchart's avatar Laurent Pinchart Committed by Vinod Koul
Browse files

dmaengine: xilinx: dpdma: Print debug message when losing vsync race 



The hardware retrigger is inherently racy with the vsync interrupt. This
isn't an issue as the hardware provides a way to detect a race loss and
handle it correctly. When debugging issues related to this, it's useful
to get a notification of the race loss. Add a debug message to do so.

Signed-off-by: default avatarLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Tested-by: default avatarJianqiang Chen <jianqiang.chen@xilinx.com>
Reviewed-by: default avatarJianqiang Chen <jianqiang.chen@xilinx.com>
Link: https://lore.kernel.org/r/20210520152420.23986-4-laurent.pinchart@ideasonboard.com


Signed-off-by: default avatarVinod Koul <vkoul@kernel.org>
parent 30211901

drivers/dma/xilinx/xilinx_dpdma.c

+5 −1
Original line number Diff line number Diff line
@@ -1095,8 +1095,12 @@ static void xilinx_dpdma_chan_vsync_irq(struct xilinx_dpdma_chan *chan) 
	/* If the retrigger raced with vsync, retry at the next frame. */

	sw_desc = list_first_entry(&pending->descriptors,

				   struct xilinx_dpdma_sw_desc, node);

	if (sw_desc->hw.desc_id != desc_id)

	if (sw_desc->hw.desc_id != desc_id) {

		dev_dbg(chan->xdev->dev,

			"chan%u: vsync race lost (%u != %u), retrying\n",

			chan->id, sw_desc->hw.desc_id, desc_id);

		goto out;

	}



	/*

	 * Complete the active descriptor, if any, promote the pending