Felipe,
On 28/02/18 09:53, Felipe Balbi wrote:
>
> Hi,
>
> Roger Quadros <rogerq@xxxxxx> writes:
>> In the following test we get stuck by sleeping forever in _dwc3_set_mode()
>> after which dual-role switching doesn't work.
>>
>> On dra7-evm's dual-role port,
>> - Load g_zero gadget driver and enumerate to host
>> - suspend to mem
>> - disconnect USB cable to host and connect otg cable with Pen drive in it.
>> - resume system
>> - we sleep indefinitely in _dwc3_set_mode due to.
>> dwc3_gadget_exit()->usb_del_gadget_udc()->udc_stop()->
>> dwc3_gadget_stop()->wait_event_lock_irq()
>>
>> Let's clear the DWC3_EP_END_TRANSFER_PENDING flag on all endpoints
>> so we don't wait in dwc3_gadget_stop().
>>
>> Signed-off-by: Roger Quadros <rogerq@xxxxxx>
>> ---
>> drivers/usb/dwc3/gadget.c | 14 ++++++++++++++
>> 1 file changed, 14 insertions(+)
>>
>> diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c
>> index 2bda4eb..0a360da 100644
>> --- a/drivers/usb/dwc3/gadget.c
>> +++ b/drivers/usb/dwc3/gadget.c
>> @@ -3273,6 +3273,20 @@ int dwc3_gadget_init(struct dwc3 *dwc)
>>
>> void dwc3_gadget_exit(struct dwc3 *dwc)
>> {
>> + int epnum;
>> + unsigned long flags;
>> +
>> + spin_lock_irqsave(&dwc->lock, flags);
>> + for (epnum = 2; epnum < DWC3_ENDPOINTS_NUM; epnum++) {
>> + struct dwc3_ep *dep = dwc->eps[epnum];
>> +
>> + if (!dep)
>> + continue;
>> +
>> + dep->flags &= ~DWC3_EP_END_TRANSFER_PENDING;
>> + }
>> + spin_unlock_irqrestore(&dwc->lock, flags);
>> +
>> usb_del_gadget_udc(&dwc->gadget);
>> dwc3_gadget_free_endpoints(dwc);
>
> free endpoints is a better place for this. It's already going to free
> the memory anyway. Might as well clear all flags to 0 there.
>
But it won't solve the deadlock issue. Since dwc3_gadget_free_endpoints()
is called after usb_del_gadget_udc() and the deadlock happens when
usb_del_gadget_udc()->udc_stop()->dwc3_gadget_stop()->wait_event_lock_irq()
and DWC3_EP_END_TRANSFER_PENDING flag is set.
--
cheers,
-roger
Texas Instruments Finland Oy, Porkkalankatu 22, 00180 Helsinki. Y-tunnus/Business ID: 0615521-4. Kotipaikka/Domicile: Helsinki
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