On Thu, Oct 22, 2015 at 10:46:58AM +0300, Jani Nikula wrote: > On Wed, 21 Oct 2015, Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx> wrote: > > On Wed, Oct 21, 2015 at 05:22:43PM +0300, Jani Nikula wrote: > >> commit 0706f17c307b056ff6f1848320ba82d76945a6ff > >> Author: Egbert Eich <eich@xxxxxxx> > >> 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 <linux@xxxxxxxxxxxxxxxx> > >> 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 <eich@xxxxxxx> > >> Cc: Daniel Vetter <daniel.vetter@xxxxxxxx> > >> Signed-off-by: Jani Nikula <jani.nikula@xxxxxxxxx> > >> --- > >> 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". It was already cleared in irq pre/postinstall. > 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. > > BR, > Jani. > > > > > >> } > >> > >> static irqreturn_t i965_irq_handler(int irq, void *arg) > >> -- > >> 2.1.4 > >> > >> _______________________________________________ > >> Intel-gfx mailing list > >> Intel-gfx@xxxxxxxxxxxxxxxxxxxxx > >> http://lists.freedesktop.org/mailman/listinfo/intel-gfx > > > > -- > > Ville Syrjälä > > Intel OTC > > -- > Jani Nikula, Intel Open Source Technology Center -- Ville Syrjälä Intel OTC _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx http://lists.freedesktop.org/mailman/listinfo/intel-gfx
