Patch "async_tx: Fix DMA_PREP_FENCE usage in do_async_gen_syndrome()" has been added to the 4.4-stable tree

[<gregkh@linuxfoundation.org>]

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@vger.kernel.org> know about it.


>From foo@baz Tue Apr 10 10:31:53 CEST 2018
From: Anup Patel <anup.patel@broadcom.com>
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@broadcom.com>


[ 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@broadcom.com>
Reviewed-by: Ray Jui <ray.jui@broadcom.com>
Reviewed-by: Scott Branden <scott.branden@broadcom.com>
Acked-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 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@broadcom.com are

queue-4.4/async_tx-fix-dma_prep_fence-usage-in-do_async_gen_syndrome.patch