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Commit 4a4863bf authored by Martin Schiller's avatar Martin Schiller Committed by Felipe Balbi
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usb: dwc2: Fix DMA cache alignment issues 



Insert a padding between data and the stored_xfer_buffer pointer to
ensure they are not on the same cache line.

Otherwise, the stored_xfer_buffer gets corrupted for IN URBs on
non-cache-coherent systems. (In my case: Lantiq xRX200 MIPS)

Fixes: 3bc04e28 ("usb: dwc2: host: Get aligned DMA in a more supported way")
Fixes: 56406e01 ("usb: dwc2: Fix DMA alignment to start at allocated boundary")
Cc: <stable@vger.kernel.org>
Tested-by: default avatarDouglas Anderson <dianders@chromium.org>
Reviewed-by: default avatarDouglas Anderson <dianders@chromium.org>
Acked-by: default avatarMinas Harutyunyan <hminas@synopsys.com>
Signed-off-by: default avatarMartin Schiller <ms@dev.tdt.de>
Signed-off-by: default avatarFelipe Balbi <felipe.balbi@linux.intel.com>
parent babd1839

drivers/usb/dwc2/hcd.c

+7 −3
Original line number Diff line number Diff line
@@ -2480,8 +2480,10 @@ static void dwc2_free_dma_aligned_buffer(struct urb *urb) 
		return;



	/* Restore urb->transfer_buffer from the end of the allocated area */

	memcpy(&stored_xfer_buffer, urb->transfer_buffer +

	       urb->transfer_buffer_length, sizeof(urb->transfer_buffer));

	memcpy(&stored_xfer_buffer,

	       PTR_ALIGN(urb->transfer_buffer + urb->transfer_buffer_length,

			 dma_get_cache_alignment()),

	       sizeof(urb->transfer_buffer));



	if (usb_urb_dir_in(urb)) {

		if (usb_pipeisoc(urb->pipe))
@@ -2513,6 +2515,7 @@ static int dwc2_alloc_dma_aligned_buffer(struct urb *urb, gfp_t mem_flags) 
	 * DMA

	 */

	kmalloc_size = urb->transfer_buffer_length +

		(dma_get_cache_alignment() - 1) +

		sizeof(urb->transfer_buffer);



	kmalloc_ptr = kmalloc(kmalloc_size, mem_flags);
@@ -2523,7 +2526,8 @@ static int dwc2_alloc_dma_aligned_buffer(struct urb *urb, gfp_t mem_flags) 
	 * Position value of original urb->transfer_buffer pointer to the end

	 * of allocation for later referencing

	 */

	memcpy(kmalloc_ptr + urb->transfer_buffer_length,

	memcpy(PTR_ALIGN(kmalloc_ptr + urb->transfer_buffer_length,

			 dma_get_cache_alignment()),

	       &urb->transfer_buffer, sizeof(urb->transfer_buffer));



	if (usb_urb_dir_out(urb))