Roger Quadros <rog...@ti.com> writes:
> UDC core calls .udc_set_speed() with the speed parameter
> containing the maximum speed supported by the gadget function
> driver. This might very well be more or less than that
> supported by the dwc3 controller driver.
>
> Select the lesser of the 2 speeds so both are operating
> within limits.
>
> This fixes PHY Erratic errors and 2 second enumeration delay on
> TI's AM437x platforms.
>
> Fixes: 7d8d0639565f ("usb: dwc3: gadget: implement ->udc_set_speed()")
> Cc: <sta...@vger.kernel.org> # v4.13+
> Reported-by: Dylan Howey <dylan.ho...@tennantco.com>
> Signed-off-by: Roger Quadros <rog...@ti.com>
> ---
> drivers/usb/dwc3/gadget.c | 2 ++
> 1 file changed, 2 insertions(+)
>
> diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c
> index f064f15..9f27ec0 100644
> --- a/drivers/usb/dwc3/gadget.c
> +++ b/drivers/usb/dwc3/gadget.c
> @@ -2008,6 +2008,8 @@ static void dwc3_gadget_set_speed(struct usb_gadget *g,
> unsigned long flags;
> u32 reg;
>
> + speed = min(g->max_speed, speed);
should we do that in udc core itself?
@@ -1080,8 +1080,12 @@ static inline void usb_gadget_udc_stop(struct usb_udc
*udc)
static inline void usb_gadget_udc_set_speed(struct usb_udc *udc,
enum usb_device_speed speed)
{
- if (udc->gadget->ops->udc_set_speed)
- udc->gadget->ops->udc_set_speed(udc->gadget, speed);
+ if (udc->gadget->ops->udc_set_speed) {
+ enum usb_device_speed s;
+
+ s = min(speed, udc->gadget->max_speed);
+ udc->gadget->ops->udc_set_speed(udc->gadget, s);
+ }
}
/**
then the fix applies for all UDCs.
--
balbi
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