dmaengine: mv_xor_v2: handle mv_xor_v2_prep_sw_desc() error properly

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.

Fixes: 19a340b1a820 ("dmaengine: mv_xor_v2: new driver")
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Thomas Petazzoni 2017-05-05 11:57:44 +02:00 committed by Greg Kroah-Hartman
parent f2e9d10bf1
commit f08c84d4c7

View File

@ -389,6 +389,8 @@ mv_xor_v2_prep_dma_memcpy(struct dma_chan *chan, dma_addr_t dest,
__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 *chan, dma_addr_t dest, dma_addr_t *src,
__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_chan *chan, unsigned long flags)
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;