Hi Roshan,
> -----Original Message-----
> From: Roshan Pius [mailto:rp...@chromium.org]
> Sent: Monday, February 2, 2015 11:56 PM
> To: linux-usb@vger.kernel.org
> Cc: benc...@chromium.org; Kaukab, Yousaf; Roshan Pius
> Subject: [PATCH RESEND] usb: dwc2: Fix a bug in reading the endpoint
> directions from reg.
>
> According to the DWC2 datasheet, the HWCFG1 register stores the configured
> endpoint directions for endpoints 0-15 in bit positions 0-31.
> ==========================
> Endpoint Direction (EpDir)
> This 32-bit field uses two bits per endpoint to determine the endpoint
> direction.
> Endpoint
> Bits [31:30]: Endpoint 15 direction
> Bits [29:28]: Endpoint 14 direction
> ....
> Bits [3:2]: Endpoint 1 direction
> Bits[1:0]: Endpoint 0 direction (always BIDIR) ==========================
>
> The DWC2 driver is currently interpreting the contents of the register as
> directions for endpoints 1-15 which leads to an error in determining the
> configured endpoint directions in the core because the first 2 bits determine
> the direction of endpoint 0 and not 1.
>
> This is based on testing/next branch in Felipe's git.
>
> Signed-off-by: Roshan Pius <rp...@chromium.org>
> ---
> drivers/usb/dwc2/gadget.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/usb/dwc2/gadget.c b/drivers/usb/dwc2/gadget.c index
> 50ae096..706165c 100644
> --- a/drivers/usb/dwc2/gadget.c
> +++ b/drivers/usb/dwc2/gadget.c
> @@ -3167,7 +3167,7 @@ static int s3c_hsotg_hw_cfg(struct dwc2_hsotg
> *hsotg)
> hsotg->eps_out[0] = hsotg->eps_in[0];
>
> cfg = readl(hsotg->regs + GHWCFG1);
> - for (i = 1; i < hsotg->num_of_eps; i++, cfg >>= 2) {
> + for (i = 1, cfg >>= 2; i < hsotg->num_of_eps; i++, cfg >>= 2) {
Nice catch! I wouldn't have found it on my hardware as GHWCFG1 is always 0.
> ep_type = cfg & 3;
> /* Direction in or both */
> if (!(ep_type & 2)) {
> --
> 2.2.0.rc0.207.ga3a616c
BR,
Yousaf
--
To unsubscribe from this list: send the line "unsubscribe linux-usb" in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
