Re: [PATCH v3] usb: dwc3: gadget: Handle 0 xfer length for OUT EP

[Tejas Joglekar]

Hi Felipe,
Gentle reminder... any comments on my patch ?

On 1/22/2019 1:27 PM, Tejas Joglekar wrote:
> For OUT endpoints, zero-length transfers require MaxPacketSize buffer as
> per the DWC_usb3 programming guide 3.30a section 4.2.3.3.
>
> This patch fixes this by explicitly checking zero length
> transfer to correctly pad up to MaxPacketSize.
>
> Fixes: c6267a51639b ("usb: dwc3: gadget: align transfers to wMaxPacketSize")
> Cc: sta...@vger.kernel.org
>
> Signed-off-by: Tejas Joglekar <jogle...@synopsys.com>
> ---
> Changes in v3:
>  - Enclose summary for fixes with " " and no wrap
>
> Changes in v2:
>  - Remove sg patch hunk
>  - Added fixes and stable tag
>
>  drivers/usb/dwc3/gadget.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c
> index bed2ff4..6c9b76b 100644
> --- a/drivers/usb/dwc3/gadget.c
> +++ b/drivers/usb/dwc3/gadget.c
> @@ -1119,7 +1119,7 @@ static void dwc3_prepare_one_trb_linear(struct dwc3_ep 
> *dep,
>       unsigned int maxp = usb_endpoint_maxp(dep->endpoint.desc);
>       unsigned int rem = length % maxp;
>  
> -     if (rem && usb_endpoint_dir_out(dep->endpoint.desc)) {
> +     if ((!length || rem) && usb_endpoint_dir_out(dep->endpoint.desc)) {
>               struct dwc3     *dwc = dep->dwc;
>               struct dwc3_trb *trb;
>  

Thanks,

Tejas Joglekar