dmaengine: mv_xor_v2: properly handle wrapping in the array of HW descriptors (2aab4e18) · Commits · 戴 / test

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: ("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>

drivers/dma/mv_xor_v2.c

+4 −10

Original line number	Diff line number	Diff line
		@@ -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) {

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