[PATCH] dmaengine: xilinx: dpdma: Fix race condition in vsync IRQ

From: Neel Gandhi <neel.gandhi@xilinx.com>
To: <laurent.pinchart@ideasonboard.com>, <dan.j.williams@intel.com>,
	<vkoul@kernel.org>
Cc: <michal.simek@xilinx.com>, <dmaengine@vger.kernel.org>,
	<linux-arm-kernel@lists.infradead.org>,
	<linux-kernel@vger.kernel.org>,
	Neel Gandhi <neel.gandhi@xilinx.com>
Subject: [PATCH] dmaengine: xilinx: dpdma: Fix race condition in vsync IRQ
Date: Sat, 22 Jan 2022 17:44:07 +0530	[thread overview]
Message-ID: <20220122121407.11467-1-neel.gandhi@xilinx.com> (raw)

Protected race condition of virtual DMA channel from channel queue transfer
via vchan spin lock from the caller of xilinx_dpdma_chan_queue_transfer

Signed-off-by: Neel Gandhi <neel.gandhi@xilinx.com>
---
 drivers/dma/xilinx/xilinx_dpdma.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/dma/xilinx/xilinx_dpdma.c b/drivers/dma/xilinx/xilinx_dpdma.c
index b0f4948b00a5..7d77a8948e38 100644
--- a/drivers/dma/xilinx/xilinx_dpdma.c
+++ b/drivers/dma/xilinx/xilinx_dpdma.c
@@ -1102,7 +1102,9 @@ static void xilinx_dpdma_chan_vsync_irq(struct  xilinx_dpdma_chan *chan)
        chan->desc.active = pending;
        chan->desc.pending = NULL;

+       spin_lock(&chan->vchan.lock);
        xilinx_dpdma_chan_queue_transfer(chan);
+       spin_unlock(&chan->vchan.lock);

 out:
        spin_unlock_irqrestore(&chan->lock, flags);
@@ -1495,7 +1497,9 @@ static void xilinx_dpdma_chan_err_task(struct tasklet_struct *t)
                    XILINX_DPDMA_EINTR_CHAN_ERR_MASK << chan->id);

        spin_lock_irqsave(&chan->lock, flags);
+       spin_lock(&chan->vchan.lock);
        xilinx_dpdma_chan_queue_transfer(chan);
+       spin_unlock(&chan->vchan.lock);
        spin_unlock_irqrestore(&chan->lock, flags);
 }

--
2.17.1

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