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: 3bc04e28a030 ("usb: dwc2: host: Get aligned DMA in a more supported way")
Fixes: 56406e017a88 ("usb: dwc2: Fix DMA alignment to start at allocated
boundary")
Signed-off-by: Martin Schiller <m...@dev.tdt.de>
---
drivers/usb/dwc2/hcd.c | 10 +++++++---
1 file changed, 7 insertions(+), 3 deletions(-)
diff --git a/drivers/usb/dwc2/hcd.c b/drivers/usb/dwc2/hcd.c
index dd82fa516f3f..f3035dd4db25 100644
--- a/drivers/usb/dwc2/hcd.c
+++ b/drivers/usb/dwc2/hcd.c
@@ -2664,8 +2664,10 @@ 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))
@@ -2697,6 +2699,7 @@ 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);
@@ -2707,7 +2710,8 @@ 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))
--
2.11.0
