Re: [PATCH v4 01/13] USB: ch341: fix error handling on resume

Grigori Goronzy
2016-04-29T15:11:19Z

On 2016-04-29 14:16, Johan Hovold wrote:
> On Fri, Apr 15, 2016 at 11:14:04PM +0200, Grigori Goronzy wrote:
>> This may fail, do not assume it always works.
>>
>> Signed-off-by: Grigori Goronzy <greg@chown.ath.cx>
>> ---
>> drivers/usb/serial/ch341.c | 4 +---
>> 1 file changed, 1 insertion(+), 3 deletions(-)
>>
>> diff --git a/drivers/usb/serial/ch341.c b/drivers/usb/serial/ch341.c
>> index c73808f..63df8ce 100644
>> --- a/drivers/usb/serial/ch341.c
>> +++ b/drivers/usb/serial/ch341.c
>> @@ -544,9 +544,7 @@ static int ch341_reset_resume(struct usb_serial
>> *serial)
>> priv = usb_get_serial_port_data(serial->port[0]);
>>
>> /* reconfigure ch341 serial port after bus-reset */
>> - ch341_configure(serial->dev, priv);
>> -
>> - return 0;
>> + return ch341_configure(serial->dev, priv);
>
> This is correct, but have noticed that resume is currently broken in
> that the interrupt urb is never resubmitted on resume in case the port
> is
> already open?
>
> Also ch341_configure must not use GFP_KERNEL either if called from a
> resume path (use GFP_NOIO).
>
> Care to fix this up as well?
>

Sure. How can I trigger a reset properly? AFAIR, I tried USBDEVFS_RESET
and it didn't really do what I wanted, at least the reset_resume
callback wasn't invoked.

Grigori