This is a note to let you know that I've just added the patch titled
usb: dwc2: Fix DMA cache alignment issues
to my usb git tree which can be found at
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git
in the usb-linus branch.
The patch will show up in the next release of the linux-next tree
(usually sometime within the next 24 hours during the week.)
The patch will hopefully also be merged in Linus's tree for the
next -rc kernel release.
If you have any questions about this process, please let me know.
>From 4a4863bf2e7932e584a3a462d3c6daf891142ddc Mon Sep 17 00:00:00 2001
From: Martin Schiller <ms@xxxxxxxxxx>
Date: Mon, 18 Feb 2019 07:37:30 +0100
Subject: 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: 3bc04e28a030 ("usb: dwc2: host: Get aligned DMA in a more supported way")
Fixes: 56406e017a88 ("usb: dwc2: Fix DMA alignment to start at allocated boundary")
Cc: <stable@xxxxxxxxxxxxxxx>
Tested-by: Douglas Anderson <dianders@xxxxxxxxxxxx>
Reviewed-by: Douglas Anderson <dianders@xxxxxxxxxxxx>
Acked-by: Minas Harutyunyan <hminas@xxxxxxxxxxxx>
Signed-off-by: Martin Schiller <ms@xxxxxxxxxx>
Signed-off-by: Felipe Balbi <felipe.balbi@xxxxxxxxxxxxxxx>
---
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 5c51bf5506d1..2192a2873c7c 100644
--- a/drivers/usb/dwc2/hcd.c
+++ b/drivers/usb/dwc2/hcd.c
@@ -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))
--
2.21.0
