On Mon, Sep 21, 2020 at 02:24:52PM +0200, Oliver Neukum wrote: > Am Sonntag, den 20.09.2020, 10:44 +0200 schrieb Pavel Machek: > > Move prepare to wait around, so that normal GFP_KERNEL allocation can > > be used. > > > > Signed-off-by: Pavel Machek (CIP) <pavel@xxxxxxx> > > Acked-by: Alan Stern <stern@xxxxxxxxxxxxxxxxxxx> > > Ehm. Please recheck. > > > diff --git a/drivers/usb/misc/yurex.c b/drivers/usb/misc/yurex.c > > index b2e09883c7e2..071f1debebba 100644 > > --- a/drivers/usb/misc/yurex.c > > +++ b/drivers/usb/misc/yurex.c > > @@ -489,10 +489,10 @@ static ssize_t yurex_write(struct file *file, const char __user *user_buffer, > > } > > > > /* send the data as the control msg */ > > - prepare_to_wait(&dev->waitq, &wait, TASK_INTERRUPTIBLE); > > dev_dbg(&dev->interface->dev, "%s - submit %c\n", __func__, > > dev->cntl_buffer[0]); > > - retval = usb_submit_urb(dev->cntl_urb, GFP_ATOMIC); > > + retval = usb_submit_urb(dev->cntl_urb, GFP_KERNEL); > > URB completes here. wake_up() returns the task to RUNNING. > > > + prepare_to_wait(&dev->waitq, &wait, TASK_INTERRUPTIBLE); > > Task goes to TASK_INTERRUPTIBLE > > > if (retval >= 0) > > timeout = schedule_timeout(YUREX_WRITE_TIMEOUT); > > Task turns into Sleeping Beauty until timeout > > > finish_wait(&dev->waitq, &wait); > > And here task goes into error reporting as it checks timeout. Arrgh. Now I feel stupid. (Me and Pavel both, probably.) Thanks for spotting this. Alan Stern
