From: Dan Williams Date: Fri, 20 Nov 2009 00:11:03 +0000 (-0700) Subject: ioat3: fix pq completion versus channel deallocation race X-Git-Tag: v2.6.32~52^2~1 X-Git-Url: https://openfabrics.org/gitweb/?a=commitdiff_plain;h=49954c1567cb0d70d28bb5512d471dc5bd4e2c3f;p=~emulex%2Finfiniband.git ioat3: fix pq completion versus channel deallocation race The completion of a pq operation is notified with a null descriptor appended to the end of the chain. This descriptor needs to be visible to dma clients otherwise the client is precluded from ensuring all operations are quiesced before freeing channel resources, i.e. due to descriptor polling it may get the completion notification ahead of the interrupt delivered by the null descriptor. Signed-off-by: Dan Williams --- diff --git a/drivers/dma/ioat/dma_v3.c b/drivers/dma/ioat/dma_v3.c index 189788f6351..42f6f10fb0c 100644 --- a/drivers/dma/ioat/dma_v3.c +++ b/drivers/dma/ioat/dma_v3.c @@ -571,7 +571,7 @@ __ioat3_prep_xor_lock(struct dma_chan *c, enum sum_check_flags *result, dump_desc_dbg(ioat, compl_desc); /* we leave the channel locked to ensure in order submission */ - return &desc->txd; + return &compl_desc->txd; } static struct dma_async_tx_descriptor * @@ -730,7 +730,7 @@ __ioat3_prep_pq_lock(struct dma_chan *c, enum sum_check_flags *result, dump_desc_dbg(ioat, compl_desc); /* we leave the channel locked to ensure in order submission */ - return &desc->txd; + return &compl_desc->txd; } static struct dma_async_tx_descriptor *