David

I am having trouble getting the reference to "drm_global_mutex" to link
correctly in drm/udl. The error is

ERROR: "drm_global_mutex" [drivers/gpu/drm/udl/udl.ko] undefined!
make[1]: *** [__modpost] Error 1
make: *** [modules] Error 2

This seems to be only accessed in the common drm code. Do you have a
suggestion how to get around it?

On Wed, Feb 10, 2016 at 1:35 PM, David Herrmann <dh.herrmann@gmail.com>
wrote:

> Hi
>
> On Wed, Feb 10, 2016 at 9:51 PM, Haixia Shi <hshi@chromium.org> wrote:
> >> This should rather be:
> >>
> >>         drm_release(inode, filp);
> >>         mutex_lock(&drm_global_mutex);
> >>         if (!dev->open_count && udl_device_is_unplugged(dev))
> >>                 drm_put_dev(dev);
> >>         mutex_unlock(&drm_global_mutex);
> >>
> >>         return 0;
> >>
> >> There is no reason to look at the return code of drm_release(), ever.
> >
> > But drm_release() does return a retcode. It would still make sense to
> return
> > that as-is in case any existing code relies on it.
>
> Nobody should ever return error codes from fops.release(). It is
> completely bogus. You rather confuse generic user-space that calls
> close(), than getting any benefit out of it.
>
> But TBH, I don't care. Feel free to forward the return value. But
> still, please change the order of the calls as I did.
>
> Thanks
> David
>