Messages in this thread | | | Date | Mon, 21 Sep 2020 14:52:37 +0200 | From | Pavel Machek <> | Subject | Re: [PATCH] usb: yurex: Rearrange code not to need GFP_ATOMIC |
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Hi!
> > Move prepare to wait around, so that normal GFP_KERNEL allocation can > > be used. > > > > Signed-off-by: Pavel Machek (CIP) <pavel@denx.de> > > Acked-by: Alan Stern <stern@rowland.harvard.edu> > > Ehm. Please recheck.
Sorry about that.
> > +++ 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
Is there way to do the allocations for submit_urb before the prepare_to_wait? GFP_ATOMIC would be nice to avoid... and doing GFP_ATOMIC from normal process context just because of task_state seems ... wrong.
Pavel -- DENX Software Engineering GmbH, Managing Director: Wolfgang Denk HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany [unhandled content-type:application/pgp-signature] | |