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authorThomas Petazzoni <thomas.petazzoni@free-electrons.com>2017-05-05 11:57:45 +0200
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2017-06-14 15:05:57 +0200
commit67b1684c4a5e092263b2b9fc3670450eedb620cf (patch)
tree1ad5b30d36674093bf20c060e5d0e4da6712be8a /drivers/dma
parentf08c84d4c7450135ccd90e7d4ce10335d998ea6f (diff)
dmaengine: mv_xor_v2: properly handle wrapping in the array of HW descriptors
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@free-electrons.com> Signed-off-by: Vinod Koul <vinod.koul@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/dma')
-rw-r--r--drivers/dma/mv_xor_v2.c14
1 files changed, 4 insertions, 10 deletions
diff --git a/drivers/dma/mv_xor_v2.c b/drivers/dma/mv_xor_v2.c
index e9280207ac19..bdfb36ecff81 100644
--- 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 long data)
{
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 long data)
/* 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 long data)
/* increment the next descriptor */
pending_ptr++;
+ if (pending_ptr >= MV_XOR_V2_DESC_NUM)
+ pending_ptr = 0;
}
if (num_of_pending != 0) {