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dmaengine: mv_xor_v2: properly handle wrapping in the array of HW descriptors 

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: 19a340b1a8 ("dmaengine: mv_xor_v2: new driver")
Cc: <stable@vger.kernel.org>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
hifive-unleashed-5.1
Thomas Petazzoni 2017-05-05 11:57:45 +02:00 committed by Vinod Koul
parent eb8df543e4
commit 2aab4e1815
1 changed files with 4 additions and 10 deletions
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14
drivers/dma/mv_xor_v2.c
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@ -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) {