dma: mv_xor: Flush descriptors before activating a channel

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.

Cc: <stable@vger.kernel.org>
Signed-off-by: Lior Amsalem <alior@marvell.com>
Signed-off-by: Ezequiel Garcia <ezequiel.garcia@free-electrons.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

1 files changed, 3 insertions, 5 deletions

diff --git a/drivers/dma/mv_xor.c b/drivers/dma/mv_xor.c
index 766b68ed505c..394cbc5c93e3 100644
--- a/drivers/dma/mv_xor.c
+++ b/drivers/dma/mv_xor.c
@@ -191,12 +191,10 @@ 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 = readl_relaxed(XOR_ACTIVATION(chan));
-        activation |= 0x1;
-        writel_relaxed(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)