[3.8.y.z extended stable] Patch "dma: mv_xor: Flush descriptors before activating a channel" has been added to staging queue

[Kamal Mostafa]

This is a note to let you know that I have just added a patch titled

    dma: mv_xor: Flush descriptors before activating a channel

to the linux-3.8.y-queue branch of the 3.8.y.z extended stable tree 
which can be found at:

 http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.8.y-queue

This patch is scheduled to be released in version 3.8.13.25.

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.8.y.z tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Kamal

------

>From 8bd523d94a77eac94697e971b536e7838341cc6f Mon Sep 17 00:00:00 2001
From: Ezequiel Garcia <ezequiel.garcia at free-electrons.com>
Date: Wed, 21 May 2014 14:02:35 -0700
Subject: [PATCH 39/66] dma: mv_xor: Flush descriptors before activating a
 channel

commit 5a9a55bf9157d3490b0c8c4c81d4708602c26e07 upstream.

We need to use writel() instead of writel_relaxed() when starting
a channel, to ensure all the descriptors have been flushed before
the activation.

While at it, remove the unneeded read-modify-write and make the
code simpler.

Signed-off-by: Lior Amsalem <alior at marvell.com>
Signed-off-by: Ezequiel Garcia <ezequiel.garcia at free-electrons.com>
Signed-off-by: Dan Williams <dan.j.williams at intel.com>
[ kamal: backport to 3.8-stable: context ]
Signed-off-by: Kamal Mostafa <kamal at canonical.com>
---
 drivers/dma/mv_xor.c | 8 +++-----
 1 file changed, 3 insertions(+), 5 deletions(-)

diff --git a/drivers/dma/mv_xor.c b/drivers/dma/mv_xor.c
index e17fad0..f7f1028 100644
--- a/drivers/dma/mv_xor.c
+++ b/drivers/dma/mv_xor.c
@@ -224,12 +224,10 @@ static void mv_set_mode(struct mv_xor_chan *chan,

 static void mv_chan_activate(struct mv_xor_chan *chan)
 {
-	u32 activation;
-
 	dev_dbg(mv_chan_to_devp(chan), " activate chan.\n");
-	activation = __raw_readl(XOR_ACTIVATION(chan));
-	activation |= 0x1;
-	__raw_writel(activation, XOR_ACTIVATION(chan));
+
+	/* writel ensures all descriptors are flushed before activation */
+	writel(BIT(0), XOR_ACTIVATION(chan));
 }

 static char mv_chan_is_busy(struct mv_xor_chan *chan)
--
1.9.1