Re: [PATCH] drm: don't check modeset locks in panic handler

From: Daniel Vetter
Date: Thu May 02 2013 - 16:42:14 EST


On Thu, May 02, 2013 at 12:13:08PM +0200, Borislav Petkov wrote:
> On Thu, May 02, 2013 at 09:43:05AM +0200, Daniel Vetter wrote:
> > Since we know that locking is broken in that case and it's more
> > important to not flood the dmesg with random gunk.
> >
> > Cc: Dave Airlie <airlied@xxxxxxxxx>
> > Cc: Borislav Petkov <bp@xxxxxxxxx>
> > References: https://groups.google.com/forum/?fromgroups=#!topic/linux.kernel/QFzFxSUeV4I
>
> Yeah, we have this nice redirector service on k.org which uses the
> Message-ID only and doesn't rely on some external URLs remaining stable.
> You could use that instead:
>
> Link: http://lkml.kernel.org/r/20130502000206.GH15623@xxxxxxx
>
> > Cc: stable@xxxxxxxxxxxxxxx
> > Signed-off-by: Daniel Vetter <daniel.vetter@xxxxxxxx>
> > ---
> > drivers/gpu/drm/drm_crtc.c | 4 ++++
> > 1 file changed, 4 insertions(+)
> >
> > diff --git a/drivers/gpu/drm/drm_crtc.c b/drivers/gpu/drm/drm_crtc.c
> > index 792c3e3..3be0802 100644
> > --- a/drivers/gpu/drm/drm_crtc.c
> > +++ b/drivers/gpu/drm/drm_crtc.c
> > @@ -78,6 +78,10 @@ void drm_warn_on_modeset_not_all_locked(struct drm_device *dev)
> > {
> > struct drm_crtc *crtc;
> >
> > + /* Locking is currently fubar in the panic handler. */
> > + if (oops_in_progress)
> > + return;
> > +
> > list_for_each_entry(crtc, &dev->mode_config.crtc_list, head)
> > WARN_ON(!mutex_is_locked(&crtc->mutex));
>
> Yep, thanks.
>
> Reported-and-tested-by: Borislav Petkov <bp@xxxxxxx>

Thanks for testing, patch applied to drm-intel-fixes.
-Daniel
--
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch
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