This is a note to let you know that I've just added the patch titled async_tx: Fix DMA_PREP_FENCE usage in do_async_gen_syndrome() to the 4.4-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: async_tx-fix-dma_prep_fence-usage-in-do_async_gen_syndrome.patch and it can be found in the queue-4.4 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From foo@baz Tue Apr 10 10:31:53 CEST 2018 From: Anup Patel <anup.patel@xxxxxxxxxxxx> Date: Mon, 15 May 2017 10:34:53 +0530 Subject: async_tx: Fix DMA_PREP_FENCE usage in do_async_gen_syndrome() From: Anup Patel <anup.patel@xxxxxxxxxxxx> [ Upstream commit baae03a0e2497f49704628fd0aaf993cf98e1b99 ] The DMA_PREP_FENCE is to be used when preparing Tx descriptor if output of Tx descriptor is to be used by next/dependent Tx descriptor. The DMA_PREP_FENSE will not be set correctly in do_async_gen_syndrome() when calling dma->device_prep_dma_pq() under following conditions: 1. ASYNC_TX_FENCE not set in submit->flags 2. DMA_PREP_FENCE not set in dma_flags 3. src_cnt (= (disks - 2)) is greater than dma_maxpq(dma, dma_flags) This patch fixes DMA_PREP_FENCE usage in do_async_gen_syndrome() taking inspiration from do_async_xor() implementation. Signed-off-by: Anup Patel <anup.patel@xxxxxxxxxxxx> Reviewed-by: Ray Jui <ray.jui@xxxxxxxxxxxx> Reviewed-by: Scott Branden <scott.branden@xxxxxxxxxxxx> Acked-by: Dan Williams <dan.j.williams@xxxxxxxxx> Signed-off-by: Vinod Koul <vinod.koul@xxxxxxxxx> Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- crypto/async_tx/async_pq.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) --- a/crypto/async_tx/async_pq.c +++ b/crypto/async_tx/async_pq.c @@ -62,9 +62,6 @@ do_async_gen_syndrome(struct dma_chan *c dma_addr_t dma_dest[2]; int src_off = 0; - if (submit->flags & ASYNC_TX_FENCE) - dma_flags |= DMA_PREP_FENCE; - while (src_cnt > 0) { submit->flags = flags_orig; pq_src_cnt = min(src_cnt, dma_maxpq(dma, dma_flags)); @@ -83,6 +80,8 @@ do_async_gen_syndrome(struct dma_chan *c if (cb_fn_orig) dma_flags |= DMA_PREP_INTERRUPT; } + if (submit->flags & ASYNC_TX_FENCE) + dma_flags |= DMA_PREP_FENCE; /* Drivers force forward progress in case they can not provide * a descriptor Patches currently in stable-queue which might be from anup.patel@xxxxxxxxxxxx are queue-4.4/async_tx-fix-dma_prep_fence-usage-in-do_async_gen_syndrome.patch