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From: Raag Jadav <raagjadav@gmail.com>
To: dmaengine@vger.kernel.org, Vinod Koul <vkoul@kernel.org>
Cc: Raag Jadav <raagjadav@gmail.com>,
	Ludovic Desroches <ludovic.desroches@microchip.com>,
	Dan Williams <dan.j.williams@intel.com>,
	linux-arm-kernel@lists.infradead.org,
	linux-kernel@vger.kernel.org
Subject: [PATCH] dmaengine: at_xdmac: check for non-empty xfers_list before invoking callback
Date: Sat, 29 Jun 2019 13:50:48 +0530	[thread overview]
Message-ID: <1561796448-3321-1-git-send-email-raagjadav@gmail.com> (raw)

tx descriptor retrieved from an empty xfers_list may not have valid
pointers to the callback functions.
Avoid calling dmaengine_desc_get_callback_invoke if xfers_list is empty.

Signed-off-by: Raag Jadav <raagjadav@gmail.com>
---
 drivers/dma/at_xdmac.c | 11 +++++++----
 1 file changed, 7 insertions(+), 4 deletions(-)

diff --git a/drivers/dma/at_xdmac.c b/drivers/dma/at_xdmac.c
index 627ef3e..b58ac72 100644
--- a/drivers/dma/at_xdmac.c
+++ b/drivers/dma/at_xdmac.c
@@ -1568,11 +1568,14 @@ static void at_xdmac_handle_cyclic(struct at_xdmac_chan *atchan)
 	struct at_xdmac_desc		*desc;
 	struct dma_async_tx_descriptor	*txd;
 
-	desc = list_first_entry(&atchan->xfers_list, struct at_xdmac_desc, xfer_node);
-	txd = &desc->tx_dma_desc;
+	if (!list_empty(&atchan->xfers_list)) {
+		desc = list_first_entry(&atchan->xfers_list,
+					struct at_xdmac_desc, xfer_node);
+		txd = &desc->tx_dma_desc;
 
-	if (txd->flags & DMA_PREP_INTERRUPT)
-		dmaengine_desc_get_callback_invoke(txd, NULL);
+		if (txd->flags & DMA_PREP_INTERRUPT)
+			dmaengine_desc_get_callback_invoke(txd, NULL);
+	}
 }
 
 static void at_xdmac_handle_error(struct at_xdmac_chan *atchan)
-- 
2.7.4


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             reply	other threads:[~2019-06-29  8:22 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-06-29  8:20 Raag Jadav [this message]
2019-07-01  8:00 ` [PATCH] dmaengine: at_xdmac: check for non-empty xfers_list before invoking callback Ludovic Desroches
2019-07-07 17:17 ` Vinod Koul

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