Re: [PATCH] usb: dwc2: Fix DMA cache alignment issues

[Doug Anderson]

Hi,

On Sun, Feb 17, 2019 at 10:37 PM Martin Schiller <ms@xxxxxxxxxx> wrote:
>
> 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 <ms@xxxxxxxxxx>
> ---
>  drivers/usb/dwc2/hcd.c | 10 +++++++---
>  1 file changed, 7 insertions(+), 3 deletions(-)

This patch has been in the back of my mind for a while bug I never got
around to it.  Today I was debugging memory corruption problems when
using a webcam on dwc2 on rk3288-veyron-jerry.  This patch appears to
solve my problems nicely.  Thanks!

Tested-by: Douglas Anderson <dianders@xxxxxxxxxxxx>
Reviewed-by: Douglas Anderson <dianders@xxxxxxxxxxxx>
Cc: <stable@xxxxxxxxxxxxxxx>