On 6/29/23 3:54 AM, Frank Li wrote:
> The legacy gadget driver omitted calling usb_gadget_check_config()
> to ensure that the USB device controller (UDC) has adequate resources,
> including sufficient endpoint numbers and types, to support the given
> configuration.
>
> Previously, usb_add_config() was solely invoked by the legacy gadget
> driver. Adds the necessary usb_gadget_check_config() after the bind()
> operation to fix the issue.
>
> Fixes: dce49449e04f ("usb: cdns3: allocate TX FIFO size according to composite EP number")
> Reported-by: Ravi Gunasekaran <r-gunasekaran@xxxxxx>
> Signed-off-by: Frank Li <Frank.Li@xxxxxxx>
> ---
> drivers/usb/gadget/composite.c | 4 ++++
> 1 file changed, 4 insertions(+)
>
> diff --git a/drivers/usb/gadget/composite.c b/drivers/usb/gadget/composite.c
> index 1b3489149e5e..dd9b90481b4c 100644
> --- a/drivers/usb/gadget/composite.c
> +++ b/drivers/usb/gadget/composite.c
> @@ -1125,6 +1125,10 @@ int usb_add_config(struct usb_composite_dev *cdev,
> goto done;
>
> status = bind(config);
> +
> + if (status == 0)
> + status = usb_gadget_check_config(cdev->gadget);
This will work for legacy gadgets that support only one configurations.
Take for example g_ether. It has two configurations when RNDIS is enabled.
And usb_add_config() is invoked for each configuration.
cdns3_gadget_check_config() calculates the total IN end-points based on the
ep->claimed flag.
list_for_each_entry(ep, &gadget->ep_list, ep_list) {
if (ep->claimed && (ep->address & USB_DIR_IN))
n_in++;
}
This ep->claimed flag is later cleared by usb_ep_autoconfig_reset() which is
invoked in usb_add_config(). So for multi-configurations, actual total in end points
is not taken into consideration thus resulting in incorrect fifo size allocation/check.
g_ffs is another gadget which has multiple configurations.
> +
> if (status < 0) {
> while (!list_empty(&config->functions)) {
> struct usb_function *f;
--
Regards,
Ravi
