On 8/17/2018 5:25 AM, Anurag Kumar Vulisha wrote:
> According to dwc3 databook when streams are used, it may be possible
> for the host and device become out of sync, where device may wait for
> host to issue prime transcation and host may wait for device to issue
> erdy. To avoid such deadlock, timeout needs to be implemented. After
> timeout occurs, device will first stop transfer and restart the transfer
> again. This patch does the same.
>
> Signed-off-by: Anurag Kumar Vulisha <anurag.kumar.vulisha@xxxxxxxxxx>
> ---
> Changes in v2:
> 1. Changed STREAM_TIMEOUT to STREAM_TIMEOUT_MS as suggested by
> Andy Shevchenko
> ---
> drivers/usb/dwc3/core.h | 7 +++++++
> drivers/usb/dwc3/gadget.c | 39 +++++++++++++++++++++++++++++++++++++++
> 2 files changed, 46 insertions(+)
>
> diff --git a/drivers/usb/dwc3/core.h b/drivers/usb/dwc3/core.h
> index 285ce0e..f58640f 100644
> --- a/drivers/usb/dwc3/core.h
> +++ b/drivers/usb/dwc3/core.h
> @@ -619,6 +619,11 @@ struct dwc3_event_buffer {
>
> #define DWC3_TRB_NUM 256
>
> +/*
> + * Timeout value in msecs used by stream_timeout_timer when streams are enabled
> + */
> +#define STREAM_TIMEOUT_MS 50
> +
> /**
> * struct dwc3_ep - device side endpoint representation
> * @endpoint: usb endpoint
> @@ -642,6 +647,7 @@ struct dwc3_event_buffer {
> * @name: a human readable name e.g. ep1out-bulk
> * @direction: true for TX, false for RX
> * @stream_capable: true when streams are enabled
> + * @stream_timeout_timer: timer used to aviod deadlock when streams are used
> */
> struct dwc3_ep {
> struct usb_ep endpoint;
> @@ -691,6 +697,7 @@ struct dwc3_ep {
>
> unsigned direction:1;
> unsigned stream_capable:1;
> + struct timer_list stream_timeout_timer;
> };
>
> enum dwc3_phy {
> diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c
> index b3e9e7f..8cef488 100644
> --- a/drivers/usb/dwc3/gadget.c
> +++ b/drivers/usb/dwc3/gadget.c
> @@ -254,6 +254,7 @@ int dwc3_send_gadget_generic_command(struct dwc3 *dwc, unsigned cmd, u32 param)
> }
>
> static int __dwc3_gadget_wakeup(struct dwc3 *dwc);
> +static void stream_timeout_function(struct timer_list *arg);
>
> /**
> * dwc3_send_gadget_ep_cmd - issue an endpoint command
> @@ -574,6 +575,8 @@ static int dwc3_gadget_set_ep_config(struct dwc3_ep *dep, unsigned int action)
> | DWC3_DEPCFG_STREAM_EVENT_EN
> | DWC3_DEPCFG_XFER_COMPLETE_EN;
> dep->stream_capable = true;
> + timer_setup(&dep->stream_timeout_timer,
> + stream_timeout_function, 0);
> }
>
> if (!usb_endpoint_xfer_control(desc))
> @@ -730,6 +733,9 @@ static int __dwc3_gadget_ep_disable(struct dwc3_ep *dep)
>
> trace_dwc3_gadget_ep_disable(dep);
>
> + if (dep->stream_capable)
> + del_timer(&dep->stream_timeout_timer);
> +
> dwc3_remove_requests(dwc, dep);
>
> /* make sure HW endpoint isn't stalled */
> @@ -1257,6 +1263,12 @@ static int __dwc3_gadget_kick_transfer(struct dwc3_ep *dep)
> return ret;
> }
>
> + if (starting && dep->stream_capable) {
> + dep->stream_timeout_timer.expires = jiffies +
> + msecs_to_jiffies(STREAM_TIMEOUT_MS);
> + add_timer(&dep->stream_timeout_timer);
> + }
> +
> return 0;
> }
>
> @@ -2403,6 +2415,13 @@ static void dwc3_gadget_endpoint_transfer_in_progress(struct dwc3_ep *dep,
> stop = true;
> }
>
> + /*
> + * Delete the timer that was started in __dwc3_gadget_kick_transfer()
> + * for stream capable endpoints.
> + */
> + if (dep->stream_capable)
> + del_timer(&dep->stream_timeout_timer);
> +
> dwc3_gadget_ep_cleanup_completed_requests(dep, event, status);
>
> if (stop) {
> @@ -2486,6 +2505,14 @@ static void dwc3_endpoint_interrupt(struct dwc3 *dwc,
> }
> break;
> case DWC3_DEPEVT_STREAMEVT:
> + switch (event->status) {
> + case DEPEVT_STREAMEVT_FOUND:
> + del_timer(&dep->stream_timeout_timer);
> + break;
> + case DEPEVT_STREAMEVT_NOTFOUND:
> + default:
> + dev_err(dwc->dev, "unable to find suitable stream");
> + }
Add break after this. Also, it's probably easier to read if we use
if-else case here.
> case DWC3_DEPEVT_RXTXFIFOEVT:
> break;
> }
> @@ -2587,6 +2614,18 @@ static void dwc3_stop_active_transfer(struct dwc3_ep *dep, bool force)
> }
> }
>
> +static void stream_timeout_function(struct timer_list *arg)
> +{
> + struct dwc3_ep *dep = from_timer(dep, arg, stream_timeout_timer);
> + struct dwc3 *dwc = dep->dwc;
> + unsigned long flags;
> +
> + spin_lock_irqsave(&dwc->lock, flags);
> + dwc3_stop_active_transfer(dep, true);
> + __dwc3_gadget_kick_transfer(dep);
> + spin_unlock_irqrestore(&dwc->lock, flags);
> +}
> +
> static void dwc3_clear_stall_all_ep(struct dwc3 *dwc)
> {
> u32 epnum;
Thinh
