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

Wesley Cheng
2022-07-14T17:41:08Z

Hi Thinh,

On 7/14/2022 10:38 AM, Thinh Nguyen wrote:
> 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.
>

Agreed.

> Hi Wesley,
>
> Did you try out my suggestion yet?
>

In process of testing. Will update you in a few days, since it might
take a day or so to reproduce.

Thanks
Wesley Cheng