Re: [PATCH v3 2/4] usb: dwc3: gadget: Refactor loop to avoid NULL endpoints

[Thinh Nguyen <Thinh.Nguyen@synopsys.com>]

On Wed, Feb 12, 2025, Andy Shevchenko wrote:
> Prepare the gadget driver to handle the reserved endpoints that will be
> not allocated at the initialisation time.
> 
> While at it, add a warning where the NULL endpoint should never happen.
> 
> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
> Tested-by: Ferry Toth <fntoth@gmail.com>
> ---
>  drivers/usb/dwc3/gadget.c | 22 ++++++++++++++++++----
>  1 file changed, 18 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c
> index d27af65eb08a..73cebb7d90c2 100644
> --- a/drivers/usb/dwc3/gadget.c
> +++ b/drivers/usb/dwc3/gadget.c
> @@ -547,6 +547,7 @@ static int dwc3_gadget_set_xfer_resource(struct dwc3_ep *dep)
>  int dwc3_gadget_start_config(struct dwc3 *dwc, unsigned int resource_index)
>  {
>  	struct dwc3_gadget_ep_cmd_params params;
> +	struct dwc3_ep		*dep;
>  	u32			cmd;
>  	int			i;
>  	int			ret;
> @@ -563,8 +564,13 @@ int dwc3_gadget_start_config(struct dwc3 *dwc, unsigned int resource_index)
>  		return ret;
>  
>  	/* Reset resource allocation flags */
> -	for (i = resource_index; i < dwc->num_eps && dwc->eps[i]; i++)
> -		dwc->eps[i]->flags &= ~DWC3_EP_RESOURCE_ALLOCATED;
> +	for (i = resource_index; i < dwc->num_eps; i++) {
> +		dep = dwc->eps[i];
> +		if (!dep)
> +			continue;
> +
> +		dep->flags &= ~DWC3_EP_RESOURCE_ALLOCATED;
> +	}
>  
>  	return 0;
>  }
> @@ -751,9 +757,11 @@ void dwc3_gadget_clear_tx_fifos(struct dwc3 *dwc)
>  
>  	dwc->last_fifo_depth = fifo_depth;
>  	/* Clear existing TXFIFO for all IN eps except ep0 */
> -	for (num = 3; num < min_t(int, dwc->num_eps, DWC3_ENDPOINTS_NUM);
> -	     num += 2) {
> +	for (num = 3; num < min_t(int, dwc->num_eps, DWC3_ENDPOINTS_NUM); num += 2) {
>  		dep = dwc->eps[num];
> +		if (!dep)
> +			continue;
> +
>  		/* Don't change TXFRAMNUM on usb31 version */
>  		size = DWC3_IP_IS(DWC3) ? 0 :
>  			dwc3_readl(dwc->regs, DWC3_GTXFIFOSIZ(num >> 1)) &
> @@ -3669,6 +3677,8 @@ static bool dwc3_gadget_endpoint_trbs_complete(struct dwc3_ep *dep,
>  
>  		for (i = 0; i < DWC3_ENDPOINTS_NUM; i++) {
>  			dep = dwc->eps[i];
> +			if (!dep)
> +				continue;
>  
>  			if (!(dep->flags & DWC3_EP_ENABLED))
>  				continue;
> @@ -3818,6 +3828,10 @@ static void dwc3_endpoint_interrupt(struct dwc3 *dwc,
>  	u8			epnum = event->endpoint_number;
>  
>  	dep = dwc->eps[epnum];
> +	if (!dep) {
> +		dev_warn(dwc->dev, "spurious event, endpoint %u is not allocated\n", epnum);
> +		return;
> +	}
>  
>  	if (!(dep->flags & DWC3_EP_ENABLED)) {
>  		if ((epnum > 1) && !(dep->flags & DWC3_EP_TRANSFER_STARTED))
> -- 
> 2.45.1.3035.g276e886db78b
> 

Acked-by: Thinh Nguyen <Thinh.Nguyen@synopsys.com>

Thanks,
Thinh