[PATCH] usb: dwc3: gadget: Fix match_ep callback for NXP UUU tool

[Neil Armstrong]

On 19/03/2025 23:07, Marek Vasut wrote:
> The UUU tool excepts the interrupt-in endpoint to be ep1in, otherwise
> it crashes. This is a result of the previous hard-coded EP setup in
> drivers/usb/gadget/epautoconf.c which did special-case EP allocation
> for SPL builds, and which was since converted to this callback, but
> without the special-case EP allocation in SPL part.
> 
> This reinstates the SPL part in an isolated manner, only for NXP iMX
> SoCs, only for SPL builds, and only for the ep1in interrupt-in endpoint.
> 
> Fixes: 1918b8010c32 ("usb: dwc3: gadget: Convert epautoconf workaround to match_ep callback")
> Signed-off-by: Marek Vasut <marex at denx.de>
> ---
> Cc: Alexander Sverdlin <alexander.sverdlin at siemens.com>
> Cc: Felipe Balbi <felipe.balbi at linux.intel.com>
> Cc: Lukasz Majewski <lukma at denx.de>
> Cc: Marek Vasut <marex at denx.de>
> Cc: Mattijs Korpershoek <mkorpershoek at baylibre.com>
> Cc: Neil Armstrong <neil.armstrong at linaro.org>
> Cc: Thinh Nguyen <Thinh.Nguyen at synopsys.com>
> Cc: Tom Rini <trini at konsulko.com>
> Cc: u-boot at lists.denx.de
> ---
> NOTE: This should go into master as a bugfix.
> ---
>   drivers/usb/dwc3/gadget.c | 19 ++++++++++++++++++-
>   1 file changed, 18 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c
> index e5a383407a2..477ecd02098 100644
> --- a/drivers/usb/dwc3/gadget.c
> +++ b/drivers/usb/dwc3/gadget.c
> @@ -1631,8 +1631,25 @@ usb_ep *dwc3_gadget_match_ep(struct usb_gadget *gadget,
>   		return dwc3_find_ep(gadget, "ep1in");
>   	if (usb_endpoint_is_bulk_out(desc))
>   		return dwc3_find_ep(gadget, "ep2out");
> -	if (usb_endpoint_is_int_in(desc))
> +	if (usb_endpoint_is_int_in(desc)) {
> +		/*
> +		 * Special workaround for NXP UUU tool in SPL.
> +		 *
> +		 * The tool excepts the interrupt-in endpoint to be ep1in,

Small nit: expects

> +		 * otherwise it crashes. This is a result of the previous
> +		 * hard-coded EP setup in drivers/usb/gadget/epautoconf.c
> +		 * which did special-case EP allocation for SPL builds,
> +		 * and which was since converted to this callback, but
> +		 * without the special-case EP allocation in SPL part.
> +		 *
> +		 * This reinstates the SPL part in an isolated manner,
> +		 * only for NXP iMX SoCs, only for SPL builds, and only
> +		 * for the ep1in interrupt-in endpoint.
> +		 */
> +		if (IS_ENABLED(CONFIG_MACH_IMX) && IS_ENABLED(CONFIG_XPL_BUILD))
> +			return dwc3_find_ep(gadget, "ep1in");
>   		return dwc3_find_ep(gadget, "ep3in");
> +	}
>   
>   	return NULL;
>   }