On 11/5/2021 9:23 PM, John Keeping wrote:
> UDCs should not enumerate faster than the max_speed set by the gadget
> driver. Use this to further restrict the speed set in the DWC2
> parameters so that the device will not connect faster than is supported
> by the gadget driver.
>
> For configfs-based composite devices this can be set via the max_speed
> configfs file.
>
> Signed-off-by: John Keeping <john@xxxxxxxxxxxx>
Acked-by: Minas Harutyunyan <Minas.Harutyunyan@xxxxxxxxxxxx>
> ---
> drivers/usb/dwc2/gadget.c | 18 +++++++++++++++++-
> 1 file changed, 17 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/usb/dwc2/gadget.c b/drivers/usb/dwc2/gadget.c
> index 744539b78f6c..1f39c2f1be8e 100644
> --- a/drivers/usb/dwc2/gadget.c
> +++ b/drivers/usb/dwc2/gadget.c
> @@ -3377,6 +3377,7 @@ void dwc2_hsotg_core_init_disconnected(struct dwc2_hsotg *hsotg,
> u32 val;
> u32 usbcfg;
> u32 dcfg = 0;
> + u8 speed;
> int ep;
>
> /* Kill any ep0 requests as controller will be reinitialized */
> @@ -3418,7 +3419,22 @@ void dwc2_hsotg_core_init_disconnected(struct dwc2_hsotg *hsotg,
>
> dcfg |= DCFG_EPMISCNT(1);
>
> - switch (hsotg->params.speed) {
> + speed = hsotg->params.speed;
> + if (hsotg->driver) {
> + switch (hsotg->driver->max_speed) {
> + case USB_SPEED_LOW:
> + speed = DWC2_SPEED_PARAM_LOW;
> + break;
> + case USB_SPEED_FULL:
> + if (speed != USB_SPEED_LOW)
> + speed = DWC2_SPEED_PARAM_FULL;
> + break;
> + default:
> + break;
> + }
> + }
> +
> + switch (speed) {
> case DWC2_SPEED_PARAM_LOW:
> dcfg |= DCFG_DEVSPD_LS;
> break;
>
