[PATCH] xhci: Always restore EP_SOFT_CLEAR_TOGGLE even if ep reset failed

[PATCH] xhci: Always restore EP_SOFT_CLEAR_TOGGLE even if ep reset failed

[Ding Hui]

Some devices driver call libusb_clear_halt when target ep queue
is not empty. (eg. spice client connected to qemu for usb redir)

Before commit f5249461b504 ("xhci: Clear the host side toggle
manually when endpoint is soft reset"), that works well.
But now, we got the error log:

    EP not empty, refuse reset

xhch_endpoint_reset failed and left ep_state's EP_SOFT_CLEAR_TOGGLE
bit is still on

So all the subsequent urb sumbit to the ep will fail with the
warn log:

    Can't enqueue URB while manually clearing toggle

We need restore ep_state EP_SOFT_CLEAR_TOGGLE bit after
xhci_endpoint_reset, even if it is failed.

Signed-off-by: Ding Hui <dinghui@sangfor.com.cn>
---
 drivers/usb/host/xhci.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c
index 3c41b14ecce7..e9884ae9c77d 100644
--- a/drivers/usb/host/xhci.c
+++ b/drivers/usb/host/xhci.c
@@ -3236,10 +3236,11 @@ static void xhci_endpoint_reset(struct usb_hcd *hcd,
 
 	wait_for_completion(cfg_cmd->completion);
 
-	ep->ep_state &= ~EP_SOFT_CLEAR_TOGGLE;
 	xhci_free_command(xhci, cfg_cmd);
 cleanup:
 	xhci_free_command(xhci, stop_cmd);
+	if (ep->ep_state & EP_SOFT_CLEAR_TOGGLE)
+		ep->ep_state &= ~EP_SOFT_CLEAR_TOGGLE;
 }
 
 static int xhci_check_streams_endpoint(struct xhci_hcd *xhci,
-- 
2.17.1

Re: [PATCH] xhci: Always restore EP_SOFT_CLEAR_TOGGLE even if ep reset failed

[Greg KH]

On Fri, Aug 21, 2020 at 03:06:52PM +0800, Ding Hui wrote:
> Some devices driver call libusb_clear_halt when target ep queue
> is not empty. (eg. spice client connected to qemu for usb redir)
> 
> Before commit f5249461b504 ("xhci: Clear the host side toggle
> manually when endpoint is soft reset"), that works well.
> But now, we got the error log:
> 
>     EP not empty, refuse reset
> 
> xhch_endpoint_reset failed and left ep_state's EP_SOFT_CLEAR_TOGGLE
> bit is still on
> 
> So all the subsequent urb sumbit to the ep will fail with the
> warn log:
> 
>     Can't enqueue URB while manually clearing toggle
> 
> We need restore ep_state EP_SOFT_CLEAR_TOGGLE bit after
> xhci_endpoint_reset, even if it is failed.
> 
> Signed-off-by: Ding Hui <dinghui@sangfor.com.cn>
> ---
>  drivers/usb/host/xhci.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)

Shouldn't this have a Fixes: tag on it and be backported to the affected
stable trees?

thanks,

greg k-h

Re: [PATCH] xhci: Always restore EP_SOFT_CLEAR_TOGGLE even if ep reset failed

[Mathias Nyman]

On 21.8.2020 10.31, Greg KH wrote:
> On Fri, Aug 21, 2020 at 03:06:52PM +0800, Ding Hui wrote:
>> Some devices driver call libusb_clear_halt when target ep queue
>> is not empty. (eg. spice client connected to qemu for usb redir)
>>
>> Before commit f5249461b504 ("xhci: Clear the host side toggle
>> manually when endpoint is soft reset"), that works well.
>> But now, we got the error log:
>>
>>     EP not empty, refuse reset
>>
>> xhch_endpoint_reset failed and left ep_state's EP_SOFT_CLEAR_TOGGLE
>> bit is still on
>>
>> So all the subsequent urb sumbit to the ep will fail with the
>> warn log:
>>
>>     Can't enqueue URB while manually clearing toggle
>>
>> We need restore ep_state EP_SOFT_CLEAR_TOGGLE bit after
>> xhci_endpoint_reset, even if it is failed.
>>
>> Signed-off-by: Ding Hui <dinghui@sangfor.com.cn>

Thanks, nice catch.

>> ---
>>  drivers/usb/host/xhci.c | 3 ++-
>>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> Shouldn't this have a Fixes: tag on it and be backported to the affected
> stable trees?

It should, but I like this patch and want it in, so I'll add the tags this time.

Thanks
-Mathias

Re: [PATCH] xhci: Always restore EP_SOFT_CLEAR_TOGGLE even if ep reset failed

[Ding Hui]

On 2020/8/21 4:44 下午, Mathias Nyman wrote:
> On 21.8.2020 10.31, Greg KH wrote:
>> On Fri, Aug 21, 2020 at 03:06:52PM +0800, Ding Hui wrote:
>>> Some devices driver call libusb_clear_halt when target ep queue
>>> is not empty. (eg. spice client connected to qemu for usb redir)
>>>
>>> Before commit f5249461b504 ("xhci: Clear the host side toggle
>>> manually when endpoint is soft reset"), that works well.
>>> But now, we got the error log:
>>>
>>>      EP not empty, refuse reset
>>>
>>> xhch_endpoint_reset failed and left ep_state's EP_SOFT_CLEAR_TOGGLE
>>> bit is still on
>>>
>>> So all the subsequent urb sumbit to the ep will fail with the
>>> warn log:
>>>
>>>      Can't enqueue URB while manually clearing toggle
>>>
>>> We need restore ep_state EP_SOFT_CLEAR_TOGGLE bit after
>>> xhci_endpoint_reset, even if it is failed.
>>>
>>> Signed-off-by: Ding Hui <dinghui@sangfor.com.cn>
> 
> Thanks, nice catch.
> 
>>> ---
>>>   drivers/usb/host/xhci.c | 3 ++-
>>>   1 file changed, 2 insertions(+), 1 deletion(-)
>>
>> Shouldn't this have a Fixes: tag on it and be backported to the affected
>> stable trees?

Sorry for missing the tags, this is my first kernel patch :-)

> 
> It should, but I like this patch and want it in, so I'll add the tags this time.

Thanks for correcting my commit msg

> 
> Thanks
> -Mathias
> 


-- 
Thanks,
-dinghui