4.9-stable review patch. If anyone has any objections, please let me know.
------------------
From: Thomas Petazzoni <thomas.petazzoni@xxxxxxxxxxxxxxxxxx>
commit 2aab4e18152cd30cb5d2f4c27629fc8a04aed979 upstream.
mv_xor_v2_tasklet() is looping over completed HW descriptors. Before the
loop, it initializes 'next_pending_hw_desc' to the first HW descriptor
to handle, and then the loop simply increments this point, without
taking care of wrapping when we reach the last HW descriptor. The
'pending_ptr' index was being wrapped back to 0 at the end, but it
wasn't used in each iteration of the loop to calculate
next_pending_hw_desc.
This commit fixes that, and makes next_pending_hw_desc a variable local
to the loop itself.
Fixes: 19a340b1a820 ("dmaengine: mv_xor_v2: new driver")
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Vinod Koul <vinod.koul@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/dma/mv_xor_v2.c | 14 ++++----------
1 file changed, 4 insertions(+), 10 deletions(-)
--- a/drivers/dma/mv_xor_v2.c
+++ b/drivers/dma/mv_xor_v2.c
@@ -560,7 +560,6 @@ static void mv_xor_v2_tasklet(unsigned l
{
struct mv_xor_v2_device *xor_dev = (struct mv_xor_v2_device *) data;
int pending_ptr, num_of_pending, i;
- struct mv_xor_v2_descriptor *next_pending_hw_desc = NULL;
struct mv_xor_v2_sw_desc *next_pending_sw_desc = NULL;
dev_dbg(xor_dev->dmadev.dev, "%s %d\n", __func__, __LINE__);
@@ -568,17 +567,10 @@ static void mv_xor_v2_tasklet(unsigned l
/* get the pending descriptors parameters */
num_of_pending = mv_xor_v2_get_pending_params(xor_dev, &pending_ptr);
- /* next HW descriptor */
- next_pending_hw_desc = xor_dev->hw_desq_virt + pending_ptr;
-
/* loop over free descriptors */
for (i = 0; i < num_of_pending; i++) {
-
- if (pending_ptr > MV_XOR_V2_DESC_NUM)
- pending_ptr = 0;
-
- if (next_pending_sw_desc != NULL)
- next_pending_hw_desc++;
+ struct mv_xor_v2_descriptor *next_pending_hw_desc =
+ xor_dev->hw_desq_virt + pending_ptr;
/* get the SW descriptor related to the HW descriptor */
next_pending_sw_desc =
@@ -614,6 +606,8 @@ static void mv_xor_v2_tasklet(unsigned l
/* increment the next descriptor */
pending_ptr++;
+ if (pending_ptr >= MV_XOR_V2_DESC_NUM)
+ pending_ptr = 0;
}
if (num_of_pending != 0) {