Re: [PATCH 5/6] usb: gadget: Add full ep_matches() check past .match_ep() callback

[Mattijs Korpershoek <mkorpershoek@baylibre.com>]

Hi Marek,

Thank you for the patch.

On dim., juin 09, 2024 at 23:32, Marek Vasut <marek.vasut+renesas@mailbox.org> wrote:

> If .match_ep() callback returns non-NULL endpoint, immediately check
> its usability and if the returned endpoint is usable, stop search and
> return the endpoint. Otherwise, continue with best effort search for
> usable endpoint.
>
> Currently the code would attempt the best effort search in any case,
> which may find another unexpected endpoint. It is likely that the
> intention of the original code was to stop the search early.
>
> Fixes: 77dcbdf3c1ce ("usb: gadget: Add match_ep() op to usb_gadget_ops")
> Signed-off-by: Marek Vasut <marek.vasut+renesas@mailbox.org>

I've added Vignesh to the CC list since he is the author of
77dcbdf3c1ce. He might be able to comment if this was indeed a mistake.

It looks like a good fix to me as well. With this change we match more closely
the linux implementation (usb_ep_autoconfig_ss()).

Reviewed-by: Mattijs Korpershoek <mkorpershoek@baylibre.com>
Tested-by: Mattijs Korpershoek <mkorpershoek@baylibre.com> # on vim3

> ---
> Cc: Alexander Sverdlin <alexander.sverdlin@siemens.com>
> Cc: Felipe Balbi <felipe.balbi@linux.intel.com>
> Cc: Lukasz Majewski <lukma@denx.de>
> Cc: Mattijs Korpershoek <mkorpershoek@baylibre.com>
> Cc: Nishanth Menon <nm@ti.com>
> Cc: Simon Glass <sjg@chromium.org>
> Cc: Thinh Nguyen <Thinh.Nguyen@synopsys.com>
> Cc: Tom Rini <trini@konsulko.com>
> Cc: u-boot@lists.denx.de
> ---
>  drivers/usb/gadget/epautoconf.c | 5 ++++-
>  1 file changed, 4 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/usb/gadget/epautoconf.c b/drivers/usb/gadget/epautoconf.c
> index 09950ceeaed..66599ce8efa 100644
> --- a/drivers/usb/gadget/epautoconf.c
> +++ b/drivers/usb/gadget/epautoconf.c
> @@ -247,8 +247,11 @@ struct usb_ep *usb_ep_autoconfig(
>  			return ep;
>  	}
>  
> -	if (gadget->ops->match_ep)
> +	if (gadget->ops->match_ep) {
>  		ep = gadget->ops->match_ep(gadget, desc, NULL);
> +		if (ep && ep_matches(gadget, ep, desc))
> +			return ep;
> +	}
>  
>  	/* Second, look at endpoints until an unclaimed one looks usable */
>  	list_for_each_entry(ep, &gadget->ep_list, ep_list) {
> -- 
> 2.43.0