Re: [PATCH v2 3/5] usb: dwc3: gadget: Adjust IRQ management during soft disconnect/connect

Thinh Nguyen
2022-07-14T18:23:19Z

On 7/12/2022, Wesley Cheng wrote:
> Local interrupts are currently being disabled as part of aquiring the
> spin lock before issuing the endxfer command. Leave interrupts enabled, so
> that EP0 events can continue to be processed. Also, ensure that there are
> no pending interrupts before attempting to handle any soft
> connect/disconnect.
>
> Fixes: 861c010a2ee1 ("usb: dwc3: gadget: Refactor pullup()")
> Signed-off-by: Wesley Cheng <quic_wcheng@quicinc.com>
> ---
> drivers/usb/dwc3/gadget.c | 21 ++++++++++++---------
> 1 file changed, 12 insertions(+), 9 deletions(-)
>
> diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c
> index a455f8d4631d..ee85b773e3fe 100644
> --- a/drivers/usb/dwc3/gadget.c
> +++ b/drivers/usb/dwc3/gadget.c
> @@ -1674,6 +1674,7 @@ static int __dwc3_gadget_get_frame(struct dwc3 *dwc)
> static int __dwc3_stop_active_transfer(struct dwc3_ep *dep, bool force, bool interrupt)
> {
> struct dwc3_gadget_ep_cmd_params params;
> + struct dwc3 *dwc = dep->dwc;
> u32 cmd;
> int ret;
>
> @@ -1682,7 +1683,9 @@ static int __dwc3_stop_active_transfer(struct dwc3_ep *dep, bool force, bool int
> cmd |= interrupt ? DWC3_DEPCMD_CMDIOC : 0;
> cmd |= DWC3_DEPCMD_PARAM(dep->resource_index);
> memset(&params, 0, sizeof(params));
> + spin_unlock(&dwc->lock);
> ret = dwc3_send_gadget_ep_cmd(dep, cmd, &params);
> + spin_lock(&dwc->lock);
> WARN_ON_ONCE(ret);
> dep->resource_index = 0;
>
> @@ -2029,12 +2032,11 @@ static int dwc3_gadget_ep_dequeue(struct usb_ep *ep,
> struct dwc3_ep *dep = to_dwc3_ep(ep);
> struct dwc3 *dwc = dep->dwc;
>
> - unsigned long flags;
> int ret = 0;
>
> trace_dwc3_ep_dequeue(req);
>
> - spin_lock_irqsave(&dwc->lock, flags);
> + spin_lock(&dwc->lock);
>
> list_for_each_entry(r, &dep->cancelled_list, list) {
> if (r == req)
> @@ -2073,7 +2075,7 @@ static int dwc3_gadget_ep_dequeue(struct usb_ep *ep,
> request, ep->name);
> ret = -EINVAL;
> out:
> - spin_unlock_irqrestore(&dwc->lock, flags);
> + spin_unlock(&dwc->lock);
>
> return ret;
> }
> @@ -2489,9 +2491,7 @@ static int __dwc3_gadget_start(struct dwc3 *dwc);
>
> static int dwc3_gadget_soft_disconnect(struct dwc3 *dwc)
> {
> - unsigned long flags;
> -
> - spin_lock_irqsave(&dwc->lock, flags);
> + spin_lock(&dwc->lock);
> dwc->connected = false;
>
> /*
> @@ -2506,10 +2506,10 @@ static int dwc3_gadget_soft_disconnect(struct dwc3 *dwc)
>
> reinit_completion(&dwc->ep0_in_setup);
>
> - spin_unlock_irqrestore(&dwc->lock, flags);
> + spin_unlock(&dwc->lock);
> ret = wait_for_completion_timeout(&dwc->ep0_in_setup,
> msecs_to_jiffies(DWC3_PULL_UP_TIMEOUT));
> - spin_lock_irqsave(&dwc->lock, flags);
> + spin_lock(&dwc->lock);
> if (ret == 0)
> dev_warn(dwc->dev, "timed out waiting for SETUP phase\n");
> }
> @@ -2523,7 +2523,7 @@ static int dwc3_gadget_soft_disconnect(struct dwc3 *dwc)
> */
> dwc3_stop_active_transfers(dwc);
> __dwc3_gadget_stop(dwc);
> - spin_unlock_irqrestore(&dwc->lock, flags);
> + spin_unlock(&dwc->lock);
>
> /*
> * Note: if the GEVNTCOUNT indicates events in the event buffer, the
> @@ -2569,6 +2569,8 @@ static int dwc3_gadget_pullup(struct usb_gadget *g, int is_on)
> return 0;
> }
>
> + synchronize_irq(dwc->irq_gadget);
> +
> if (!is_on) {
> ret = dwc3_gadget_soft_disconnect(dwc);
> } else {
> @@ -3729,6 +3731,7 @@ void dwc3_stop_active_transfer(struct dwc3_ep *dep, bool force,
> */
>
> __dwc3_stop_active_transfer(dep, force, interrupt);
> +
> }
>
> static void dwc3_clear_stall_all_ep(struct dwc3 *dwc)

Hi Greg,

Please don't pick up this patch yet. We're still in discussion with
this. I have some concern with unlocking/locking when sending End
Transfer command. For example, this patch may cause issues with
DWC3_EP_END_TRANSFER_PENDING checks.

Hi Wesley,

Did you try out my suggestion yet?

Thanks,
Thinh