On 04/04/2017 01:09 AM, Felipe Balbi wrote:
>
> Hi John,
>
> Felipe Balbi <felipe.balbi@xxxxxxxxxxxxxxx> writes:
>> At least macOS seems to be sending
>> ClearFeature(ENDPOINT_HALT) to endpoints which
>> aren't Halted. This makes DWC3's CLEARSTALL command
>> time out which causes several issues for the driver.
>>
>> Instead, let's just return 0 and bail out early.
>>
>> Cc: <stable@xxxxxxxxxxxxxxx>
>> Signed-off-by: Felipe Balbi <felipe.balbi@xxxxxxxxxxxxxxx>
>> ---
>>
>> this falls into "has never worked before" category, so I'll be sending
>> it together with other patches for v4.11 merge window. Still, it's a
>> valid bug that's likely needed for stable trees.
>>
>> drivers/usb/dwc3/gadget.c | 5 +++++
>> 1 file changed, 5 insertions(+)
>>
>> diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c
>> index 6faf484e5dfc..0a664d8eba3f 100644
>> --- a/drivers/usb/dwc3/gadget.c
>> +++ b/drivers/usb/dwc3/gadget.c
>> @@ -1379,6 +1379,9 @@ int __dwc3_gadget_ep_set_halt(struct dwc3_ep *dep, int value, int protocol)
>> unsigned transfer_in_flight;
>> unsigned started;
>>
>> + if (dep->flags & DWC3_EP_STALL)
>> + return 0;
>> +
>> if (dep->number > 1)
>> trb = dwc3_ep_prev_trb(dep, dep->trb_enqueue);
>> else
>> @@ -1400,6 +1403,8 @@ int __dwc3_gadget_ep_set_halt(struct dwc3_ep *dep, int value, int protocol)
>> else
>> dep->flags |= DWC3_EP_STALL;
>> } else {
>> + if (!(dep->flags & DWC3_EP_STALL))
>> + return 0;
>>
>> ret = dwc3_send_clear_stall_ep_cmd(dep);
>> if (ret)
>
> Reviving this old thread here. While $subject allowed dwc3 to work when
> attached to macOS Host, I fear that we might have more issues than not
> in the future. The reason is that USB20 spec allows hosts to use
> ClearFeature(ENDPOINT_HALT) as a "Reset Data Toggle/SeqN" hint.
>
> With this, we're basically blocking that possibility. Still, without
> $subject, ClearStall commands were timing out. I'll try to do a local
> revert here and check what happens in this case, but would you have any
> idea why ClearStall would time out like that?
>
Hi Felipe,
I think Thinh Nguyen e-mailed you about this before saying it caused a
regression for us. But he has not had time to look into it further and
follow-up yet.
No idea about the timing out on Mac though. We can try to reproduce
this when we have some time and take a look. Do you have a USB trace?
Regards,
John