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authorLaurent Pinchart <laurent.pinchart@ideasonboard.com>2021-05-20 18:24:19 +0300
committerVinod Koul <vkoul@kernel.org>2021-05-31 07:07:39 +0300
commit4fbf41ce573556a6dc4e684f0d92700cdc883ad3 (patch)
treef8f61fde9b1432d713c32ac42ffa268bbe95935c /drivers/dma
parent30211901927a2a504adae2a75f9863962d2d06b0 (diff)
downloadlinux-4fbf41ce573556a6dc4e684f0d92700cdc883ad3.tar.xz
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: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Tested-by: Jianqiang Chen <jianqiang.chen@xilinx.com> Reviewed-by: Jianqiang Chen <jianqiang.chen@xilinx.com> Link: https://lore.kernel.org/r/20210520152420.23986-4-laurent.pinchart@ideasonboard.com Signed-off-by: Vinod Koul <vkoul@kernel.org>
Diffstat (limited to 'drivers/dma')
-rw-r--r--drivers/dma/xilinx/xilinx_dpdma.c6
1 files changed, 5 insertions, 1 deletions
diff --git a/drivers/dma/xilinx/xilinx_dpdma.c b/drivers/dma/xilinx/xilinx_dpdma.c
index ea56c3b35782..5834f8614a58 100644
--- a/drivers/dma/xilinx/xilinx_dpdma.c
+++ b/drivers/dma/xilinx/xilinx_dpdma.c
@@ -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