Patch "dmaengine: mv_xor_v2: handle mv_xor_v2_prep_sw_desc() error properly" has been added to the 4.9-stable tree

This is a note to let you know that I've just added the patch titled

dmaengine: mv_xor_v2: handle mv_xor_v2_prep_sw_desc() error properly

to the 4.9-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
dmaengine-mv_xor_v2-handle-mv_xor_v2_prep_sw_desc-error-properly.patch
and it can be found in the queue-4.9 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

From: Thomas Petazzoni <[email protected]>
Date: Fri, 5 May 2017 11:57:44 +0200
Subject: dmaengine: mv_xor_v2: handle mv_xor_v2_prep_sw_desc() error properly

From: Thomas Petazzoni <[email protected]>

commit eb8df543e444492328f506adffc7dfe94111f1bd upstream.

The mv_xor_v2_prep_sw_desc() is called from a few different places in the driver, but we never take into account the fact that it might return NULL. This commit fixes that, ensuring that we don't panic if there are no more descriptors available.

---
 drivers/dma/mv_xor_v2.c |    6 ++++++
 1 file changed, 6 insertions(+)

@@ -389,6 +389,8 @@ mv_xor_v2_prep_dma_memcpy(struct dma_cha
 		__func__, len, &src, &dest, flags);
 
 	sw_desc = mv_xor_v2_prep_sw_desc(xor_dev);
+	if (!sw_desc)
+		return NULL;
 
 	sw_desc->async_tx.flags = flags;
 

@@ -443,6 +445,8 @@ mv_xor_v2_prep_dma_xor(struct dma_chan *
 		__func__, src_cnt, len, &dest, flags);
 
 	sw_desc = mv_xor_v2_prep_sw_desc(xor_dev);
+	if (!sw_desc)
+		return NULL;
 
 	sw_desc->async_tx.flags = flags;
 

@@ -491,6 +495,8 @@ mv_xor_v2_prep_dma_interrupt(struct dma_
 		container_of(chan, struct mv_xor_v2_device, dmachan);
 
 	sw_desc = mv_xor_v2_prep_sw_desc(xor_dev);
+	if (!sw_desc)
+		return NULL;
 
 	/* set the HW descriptor */
 	hw_descriptor = &sw_desc->hw_desc;

Patches currently in stable-queue which might be from [email protected] are

queue-4.9/dmaengine-mv_xor_v2-properly-handle-wrapping-in-the-array-of-hw-descriptors.patch queue-4.9/dmaengine-mv_xor_v2-enable-xor-engine-after-its-configuration.patch queue-4.9/dmaengine-mv_xor_v2-set-dma-mask-to-40-bits.patch queue-4.9/dmaengine-mv_xor_v2-do-not-use-descriptors-not-acked-by-async_tx.patch queue-4.9/dmaengine-mv_xor_v2-handle-mv_xor_v2_prep_sw_desc-error-properly.patch queue-4.9/dmaengine-mv_xor_v2-remove-interrupt-coalescing.patch queue-4.9/dmaengine-mv_xor_v2-fix-tx_submit-implementation.patch