On Thu, Oct 22, 2015 at 10:46:58AM +0300, Jani Nikula wrote: > On Wed, 21 Oct 2015, Ville Syrjälä <ville.syrj...@linux.intel.com> wrote: > > On Wed, Oct 21, 2015 at 05:22:43PM +0300, Jani Nikula wrote: > >> commit 0706f17c307b056ff6f1848320ba82d76945a6ff > >> Author: Egbert Eich <e...@suse.de> > >> Date: Wed Sep 23 16:15:27 2015 +0200 > >> > >> drm/i915: Avoid race of intel_crt_detect_hotplug() with HPD interrupt, > >> v2 > >> > >> added a check with WARN to ensure only bits within the mask are > >> enabled. Turns out that doesn't hold for G4X, which spits out: > >> > >> [ 2.641439] ------------[ cut here ]------------ > >> [ 2.641444] WARNING: CPU: 0 PID: 1 at > >> drivers/gpu/drm/i915/i915_irq.c:182 > >> i915_hotplug_interrupt_update_locked+0x45/0x83() > >> [ 2.641446] WARN_ON(bits & ~mask) > >> etc. > >> > >> Add CRT_HOTPLUG_ACTIVATION_PERIOD_64 to the mask to fix the warning. > >> > >> Reported-by: Oleksij Rempel <li...@rempel-privat.de> > >> References: https://bugzilla.kernel.org/show_bug.cgi?id=104991 > >> Fixes: 0706f17c307b ("drm/i915: Avoid race of intel_crt_detect_hotplug() > >> with HPD interrupt, v2") > >> Cc: Egbert Eich <e...@suse.de> > >> Cc: Daniel Vetter <daniel.vet...@ffwll.ch> > >> Signed-off-by: Jani Nikula <jani.nik...@intel.com> > >> --- > >> drivers/gpu/drm/i915/i915_irq.c | 7 ++++--- > >> 1 file changed, 4 insertions(+), 3 deletions(-) > >> > >> diff --git a/drivers/gpu/drm/i915/i915_irq.c > >> b/drivers/gpu/drm/i915/i915_irq.c > >> index 7f91f74961f4..5b9f63d4318b 100644 > >> --- a/drivers/gpu/drm/i915/i915_irq.c > >> +++ b/drivers/gpu/drm/i915/i915_irq.c > >> @@ -4236,9 +4236,10 @@ static void i915_hpd_irq_setup(struct drm_device > >> *dev) > >> > >> /* Ignore TV since it's buggy */ > >> i915_hotplug_interrupt_update_locked(dev_priv, > >> - (HOTPLUG_INT_EN_MASK > >> - | CRT_HOTPLUG_VOLTAGE_COMPARE_MASK), > >> - hotplug_en); > >> + HOTPLUG_INT_EN_MASK | > >> + CRT_HOTPLUG_VOLTAGE_COMPARE_MASK | > >> + CRT_HOTPLUG_ACTIVATION_PERIOD_64, > >> + hotplug_en); > > > > Or maybe just ~CRT_HOTPLUG_FORCE_DETECT ? > > This patch already potentially changes behaviour by explicitly setting > the activation period to zero (CRT_HOTPLUG_ACTIVATION_PERIOD_32) on > non-g4x. Previously it was "don't care". Call me coward, but I am not > comfortable with setting the rest of the bits to zero, at least not in > the context of this fix, and risking regressions on old machines.
Might be a notch too paranoid, but we've always had that rmw in there. Reviewed-by: Daniel Vetter <daniel.vet...@ffwll.ch> > > BR, > Jani. > > > > > >> } > >> > >> static irqreturn_t i965_irq_handler(int irq, void *arg) > >> -- > >> 2.1.4 > >> > >> _______________________________________________ > >> Intel-gfx mailing list > >> Intel-gfx@lists.freedesktop.org > >> http://lists.freedesktop.org/mailman/listinfo/intel-gfx > > > > -- > > Ville Syrjälä > > Intel OTC > > -- > Jani Nikula, Intel Open Source Technology Center -- Daniel Vetter Software Engineer, Intel Corporation http://blog.ffwll.ch _______________________________________________ Intel-gfx mailing list Intel-gfx@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/intel-gfx
