Re: [Patch v2] usb: dwc3: add cancelled reasons for dwc3 requests

[Thinh Nguyen]

Hi Ray,

Ray Chi wrote:
> Currently, when dwc3 handles request cancelled, dwc3 just returns
> -ECONNRESET for all requests. It will cause USB function drivers
> can't know if the requests are cancelled by other reasons.
> 
> This patch will replace DWC3_REQUEST_STATUS_CANCELLED with the
> reasons below.
>   - DWC3_REQUEST_STATUS_DISCONNECTED
>   - DWC3_REQUEST_STATUS_DEQUEUED
>   - DWC3_REQUEST_STATUS_STALLED
> 
> Signed-off-by: Ray Chi <raychi@xxxxxxxxxx>
> ---
>  drivers/usb/dwc3/core.h   | 12 +++++++-----
>  drivers/usb/dwc3/gadget.c | 21 +++++++++++++++++----
>  drivers/usb/dwc3/gadget.h |  6 ++++--
>  3 files changed, 28 insertions(+), 11 deletions(-)
> 
> diff --git a/drivers/usb/dwc3/core.h b/drivers/usb/dwc3/core.h
> index 4ca4b4be85e4..51a3eec2428a 100644
> --- a/drivers/usb/dwc3/core.h
> +++ b/drivers/usb/dwc3/core.h
> @@ -908,11 +908,13 @@ struct dwc3_request {
>  	unsigned int		remaining;
>  
>  	unsigned int		status;
> -#define DWC3_REQUEST_STATUS_QUEUED	0
> -#define DWC3_REQUEST_STATUS_STARTED	1
> -#define DWC3_REQUEST_STATUS_CANCELLED	2
> -#define DWC3_REQUEST_STATUS_COMPLETED	3
> -#define DWC3_REQUEST_STATUS_UNKNOWN	-1
> +#define DWC3_REQUEST_STATUS_QUEUED		0
> +#define DWC3_REQUEST_STATUS_STARTED		1
> +#define DWC3_REQUEST_STATUS_DISCONNECTED	2
> +#define DWC3_REQUEST_STATUS_DEQUEUED		3
> +#define DWC3_REQUEST_STATUS_STALLED		4
> +#define DWC3_REQUEST_STATUS_COMPLETED		5
> +#define DWC3_REQUEST_STATUS_UNKNOWN		-1
>  
>  	u8			epnum;
>  	struct dwc3_trb		*trb;
> diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c
> index e1442fc763e1..b11fd02604bb 100644
> --- a/drivers/usb/dwc3/gadget.c
> +++ b/drivers/usb/dwc3/gadget.c
> @@ -1402,7 +1402,7 @@ static int __dwc3_gadget_kick_transfer(struct dwc3_ep *dep)
>  		dwc3_stop_active_transfer(dep, true, true);
>  
>  		list_for_each_entry_safe(req, tmp, &dep->started_list, list)
> -			dwc3_gadget_move_cancelled_request(req);
> +			dwc3_gadget_move_cancelled_request(req, DWC3_REQUEST_STATUS_DEQUEUED);
>  
>  		/* If ep isn't started, then there's no end transfer pending */
>  		if (!(dep->flags & DWC3_EP_END_TRANSFER_PENDING))
> @@ -1732,7 +1732,19 @@ static void dwc3_gadget_ep_cleanup_cancelled_requests(struct dwc3_ep *dep)
>  
>  	list_for_each_entry_safe(req, tmp, &dep->cancelled_list, list) {
>  		dwc3_gadget_ep_skip_trbs(dep, req);
> -		dwc3_gadget_giveback(dep, req, -ECONNRESET);
> +		switch (req->status) {
> +		case DWC3_REQUEST_STATUS_DISCONNECTED:
> +			dwc3_gadget_giveback(dep, req, -ESHUTDOWN);
> +			break;
> +		case DWC3_REQUEST_STATUS_DEQUEUED:
> +			dwc3_gadget_giveback(dep, req, -ECONNRESET);
> +			break;
> +		case DWC3_REQUEST_STATUS_STALLED:
> +			dwc3_gadget_giveback(dep, req, -EPIPE);
> +			break;
> +		default:

Also giveback the request for default case here, but with -ECONNRESET
and a dev_err() print here indicating driver bug. The rest of the patch
looks good.

Thanks,
Thinh

> +			break;
> +		}
>  	}
>  }
>  
> @@ -1776,7 +1788,8 @@ static int dwc3_gadget_ep_dequeue(struct usb_ep *ep,
>  			 * cancelled.
>  			 */
>  			list_for_each_entry_safe(r, t, &dep->started_list, list)
> -				dwc3_gadget_move_cancelled_request(r);
> +				dwc3_gadget_move_cancelled_request(r,
> +						DWC3_REQUEST_STATUS_DEQUEUED);
>  
>  			dep->flags &= ~DWC3_EP_WAIT_TRANSFER_COMPLETE;
>  
> @@ -1848,7 +1861,7 @@ int __dwc3_gadget_ep_set_halt(struct dwc3_ep *dep, int value, int protocol)
>  		dwc3_stop_active_transfer(dep, true, true);
>  
>  		list_for_each_entry_safe(req, tmp, &dep->started_list, list)
> -			dwc3_gadget_move_cancelled_request(req);
> +			dwc3_gadget_move_cancelled_request(req, DWC3_REQUEST_STATUS_STALLED);
>  
>  		if (dep->flags & DWC3_EP_END_TRANSFER_PENDING) {
>  			dep->flags |= DWC3_EP_PENDING_CLEAR_STALL;
> diff --git a/drivers/usb/dwc3/gadget.h b/drivers/usb/dwc3/gadget.h
> index 0cd281949970..77df4b6d6c13 100644
> --- a/drivers/usb/dwc3/gadget.h
> +++ b/drivers/usb/dwc3/gadget.h
> @@ -90,15 +90,17 @@ static inline void dwc3_gadget_move_started_request(struct dwc3_request *req)
>  /**
>   * dwc3_gadget_move_cancelled_request - move @req to the cancelled_list
>   * @req: the request to be moved
> + * @reason: cancelled reason for the dwc3 request
>   *
>   * Caller should take care of locking. This function will move @req from its
>   * current list to the endpoint's cancelled_list.
>   */
> -static inline void dwc3_gadget_move_cancelled_request(struct dwc3_request *req)
> +static inline void dwc3_gadget_move_cancelled_request(struct dwc3_request *req,
> +		unsigned int reason)
>  {
>  	struct dwc3_ep		*dep = req->dep;
>  
> -	req->status = DWC3_REQUEST_STATUS_CANCELLED;
> +	req->status = reason;
>  	list_move_tail(&req->list, &dep->cancelled_list);
>  }
>  
>