On Sun, Nov 08, 2020 at 10:51:11AM +0000, Anthony Richardby wrote:
> On 2020-11-08 02:40:26 +0000 Jonathan Gray <j...@jsg.id.au> wrote:
>
> > On Sat, Nov 07, 2020 at 04:01:34PM +0000, Anthony Richardby wrote:
> > > Hey,
> > > I'm experiencing a kernel panic whenever I run glxgears, or it would
> > > seem when I try to run other gpu-related tasks. I first noticed this
> > > when playing video via the application 'mpv', after a couple of
> > > seconds of video the system freezes!! I've got the trace output for
> > > that as the time delay allows me to switch out of X11 to a console
> > > before the system crashes. Anyway after this I tried 'glxgears' and
> > > that crashes immediately (so I'm unable to get the trace, but it
> > > sounds like it's related?).
> >
> > > Just wondering if anyone else is able to reproduce this on their
> > > powerbooks / other g4 macs, does glxgears work for you?
> >
> > > Pic of the trace output: https://postimg.cc/wRLGLKdF
> >
> > What is the actual panic message?
> >
> > For the archives the trace was:
> >
> > panic(b6ae0c) at panic+0x154
> > mtx_enter(0) at mtx_enter+0x8c
> > drm_update_vblank_count(2a0fcdf8,e000a000,b6ae78) at
> > drm_update_vblank_count+0x4b8
> > drm_handle_vblank(2000611,82720e) at drm_handle_vblank+0xd8
> > r100_irq_process(a19ca0) at r100_irq_process+0x110
> > radeon_driver_irq_handler_kms(0) at radeon_driver_irq_handler_kms+0x28
> > openpic_ext_intr() at openpic_ext_intr+0x274
> > extint_call() at extint_call
> > --- interrupt ---
> > at 0xe7055e1c
> > drm_wait_vblank_ioctl(e0732f00,e06b9b84,e7055c60) at
> > drm_wait_vblank_ioctl+0xb2
> > drm_do_ioctl(251571d0) at drm_do_ioctl+0x298
> > drmioctl(25157100,e7055ca8,990000,c010643a,3a033428) at drmioctl+0xbc
> >
> >
> >
>
> The panic message is:
> panic: mtx 0xe024cc50: locking against myself
>
> I forgot to mention that this is new in 6.8, I can run glxgears/play
> video with mpv fine using 6.7.
The seqlock is used from an interrupt context
drm_update_vblank_count() -> store_vblank()
Can you try a kernel with the following diff?
Patch against 6.8 branch.
Index: sys/dev/pci/drm/drm_vblank.c
===================================================================
RCS file: /cvs/src/sys/dev/pci/drm/drm_vblank.c,v
retrieving revision 1.6
diff -u -p -r1.6 drm_vblank.c
--- sys/dev/pci/drm/drm_vblank.c 29 Jul 2020 09:52:21 -0000 1.6
+++ sys/dev/pci/drm/drm_vblank.c 8 Nov 2020 11:04:58 -0000
@@ -481,7 +481,7 @@ int drm_vblank_init(struct drm_device *d
init_waitqueue_head(&vblank->queue);
setup_timer(&vblank->disable_timer, vblank_disable_fn,
(unsigned long)vblank);
- seqlock_init(&vblank->seqlock, IPL_NONE);
+ seqlock_init(&vblank->seqlock, IPL_TTY);
}
DRM_INFO("Supports vblank timestamp caching Rev 2 (21.10.2013).\n");
