[Intel-gfx] [PATCH] drm/i915: Officially give up on seqno coherency

[Daniel Vetter]

On Tue, Jun 23, 2015 at 01:05:41PM +0300, Jani Nikula wrote:
> On Fri, 19 Jun 2015, Daniel Vetter <daniel.vetter at ffwll.ch> wrote:
> > We've never figured out the magic trick to make irq vs. seqno
> > updates coherent, only tricks to make it work. And since
> >
> > commit 094f9a54e35500739da185cdb78f2e92fc379458
> > Author: Chris Wilson <chris at chris-wilson.co.uk>
> > Date:   Wed Sep 25 17:34:55 2013 +0100
> >
> >     drm/i915: Fix __wait_seqno to use true infinite timeouts
> >
> > we automatically fall back to an irq augmented with polling scheme
> > after the first missed interrupt. There's really nothing else we can
> > do, hence tune down the message to informational level. It's still
> > useful for users in case it reliable preceedes a hard system hang.
> >
> > v2: Use NOTICE since it might be of value for bug reports (Chris).
> >
> > Cc: Mark Janes <mark.a.janes at intel.com>
> > Cc: Chris Wilson <chris at chris-wilson.co.uk>
> > Cc: stable at vger.kernel.org
> > Signed-off-by: Daniel Vetter <daniel.vetter at intel.com>
> > ---
> >  drivers/gpu/drm/i915/i915_irq.c | 4 ++--
> >  1 file changed, 2 insertions(+), 2 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/i915/i915_irq.c b/drivers/gpu/drm/i915/i915_irq.c
> > index e6bb72dca3ff..5072fb49367e 100644
> > --- a/drivers/gpu/drm/i915/i915_irq.c
> > +++ b/drivers/gpu/drm/i915/i915_irq.c
> > @@ -2946,8 +2946,8 @@ static void i915_hangcheck_elapsed(struct work_struct *work)
> >  					/* Issue a wake-up to catch stuck h/w. */
> >  					if (!test_and_set_bit(ring->id, &dev_priv->gpu_error.missed_irq_rings)) {
> >  						if (!(dev_priv->gpu_error.test_irq_rings & intel_ring_flag(ring)))
> > -							DRM_ERROR("Hangcheck timer elapsed... %s idle\n",
> > -								  ring->name);
> > +							DRM_NOTICE("Hangcheck timer elapsed... %s idle\n",
> 
> drivers/gpu/drm/i915/i915_irq.c: In function ‘i915_hangcheck_elapsed’:
> drivers/gpu/drm/i915/i915_irq.c:2949:8: error: implicit declaration of function ‘DRM_NOTICE’ [-Werror=implicit-function-declaration]
>         DRM_NOTICE("Hangcheck timer elapsed... %s idle\n",
>         ^

Embarassing. Can you pick up v1 instead please?
-Daniel
-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch