[Intel-gfx] [PATCH 3/3] drm/i915/psr: Do not activate PSR when vblank interrupts are enabled
Pandiyan, Dhinakaran
dhinakaran.pandiyan at intel.com
Wed Jun 15 01:02:45 UTC 2016
On Tue, 2016-06-14 at 00:09 +0000, Vivi, Rodrigo wrote:
> On Wed, 2016-06-08 at 18:46 -0700, Dhinakaran Pandiyan wrote:
> > PSR in CHV, unlike HSW, can get activated even if vblanks interrupts
> > are
> > enabled. But, the pipe is not expected to generate timings signals
> > when PSR is active. Specifically, we do not get vblank interrupts in
> > CHV
> > if PSR becomes active. This has led to drm_wait_vblank timing out.
> >
> > Let's disable PSR using the vblank prepare hook that gets called
> > before
> > enabling vblank interrupts and keep it disabled until the interrupts
> > are
> > not needed.
> >
> > Signed-off-by: Dhinakaran Pandiyan <dhinakaran.pandiyan at intel.com>
> > ---
> > drivers/gpu/drm/i915/i915_drv.h | 1 +
> > drivers/gpu/drm/i915/i915_irq.c | 12 ++++++++
> > drivers/gpu/drm/i915/intel_drv.h | 2 ++
> > drivers/gpu/drm/i915/intel_psr.c | 61
> > +++++++++++++++++++++++++++++++++++++++-
> > 4 files changed, 75 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/gpu/drm/i915/i915_drv.h
> > b/drivers/gpu/drm/i915/i915_drv.h
> > index e4c8e34..03f311e 100644
> > --- a/drivers/gpu/drm/i915/i915_drv.h
> > +++ b/drivers/gpu/drm/i915/i915_drv.h
> > @@ -994,6 +994,7 @@ struct i915_psr {
> > bool psr2_support;
> > bool aux_frame_sync;
> > bool link_standby;
> > + bool vlv_src_timing;
> > };
> >
> > enum intel_pch {
> > diff --git a/drivers/gpu/drm/i915/i915_irq.c
> > b/drivers/gpu/drm/i915/i915_irq.c
> > index caaf1e2..77f3d76 100644
> > --- a/drivers/gpu/drm/i915/i915_irq.c
> > +++ b/drivers/gpu/drm/i915/i915_irq.c
> > @@ -2790,6 +2790,16 @@ static int gen8_enable_vblank(struct
> > drm_device *dev, unsigned int pipe)
> > return 0;
> > }
> >
> > +static void valleyview_prepare_vblank(struct drm_device *dev,
> > unsigned int pipe)
> > +{
>
> shouldn't we force psr_exit here? What if vblank is enabled after psr
> is already in active mode?
>
vlv_psr_src_timing_get calls intel_psr_exit if PSR is already active.
> > + vlv_psr_src_timing_get(dev);
> > +}
> > +
> > +static void valleyview_unprepare_vblank(struct drm_device *dev,
> > unsigned int pipe){
> > +
> > + vlv_psr_src_timing_put(dev);
> > +}
> > +
> > /* Called from drm generic code, passed 'crtc' which
> > * we use as a pipe index
> > */
> > @@ -4610,6 +4620,8 @@ void intel_irq_init(struct drm_i915_private
> > *dev_priv)
> > dev->driver->irq_uninstall =
> > cherryview_irq_uninstall;
> > dev->driver->enable_vblank =
> > valleyview_enable_vblank;
> > dev->driver->disable_vblank =
> > valleyview_disable_vblank;
> > + dev->driver->prepare_vblank =
> > valleyview_prepare_vblank;
> > + dev->driver->unprepare_vblank =
> > valleyview_unprepare_vblank;
> > dev_priv->display.hpd_irq_setup =
> > i915_hpd_irq_setup;
> > } else if (IS_VALLEYVIEW(dev_priv)) {
> > dev->driver->irq_handler = valleyview_irq_handler;
> > diff --git a/drivers/gpu/drm/i915/intel_drv.h
> > b/drivers/gpu/drm/i915/intel_drv.h
> > index 9b5f663..e2078fd 100644
> > --- a/drivers/gpu/drm/i915/intel_drv.h
> > +++ b/drivers/gpu/drm/i915/intel_drv.h
> > @@ -1511,6 +1511,8 @@ void intel_psr_flush(struct drm_device *dev,
> > void intel_psr_init(struct drm_device *dev);
> > void intel_psr_single_frame_update(struct drm_device *dev,
> > unsigned frontbuffer_bits);
> > +void vlv_psr_src_timing_get(struct drm_device *dev);
> > +void vlv_psr_src_timing_put(struct drm_device *dev);
> >
> > /* intel_runtime_pm.c */
> > int intel_power_domains_init(struct drm_i915_private *);
> > diff --git a/drivers/gpu/drm/i915/intel_psr.c
> > b/drivers/gpu/drm/i915/intel_psr.c
> > index 29a09bf..c95e680 100644
> > --- a/drivers/gpu/drm/i915/intel_psr.c
> > +++ b/drivers/gpu/drm/i915/intel_psr.c
> > @@ -462,6 +462,7 @@ void intel_psr_enable(struct intel_dp *intel_dp)
> >
> > /* Enable PSR on the panel */
> > vlv_psr_enable_sink(intel_dp);
> > + dev_priv->psr.vlv_src_timing = false;
> >
> > /* On HSW+ enable_source also means go to PSR
> > entry/active
> > * state as soon as idle_frame achieved and here
> > would be
> > @@ -608,8 +609,10 @@ static void intel_psr_work(struct work_struct
> > *work)
> > * The delayed work can race with an invalidate hence we
> > need to
> > * recheck. Since psr_flush first clears this and then
> > reschedules we
> > * won't ever miss a flush when bailing out here.
> > + * Also, do not enable PSR if source is required to generate
> > timing
> > + * signals like vblanks.
> > */
> > - if (dev_priv->psr.busy_frontbuffer_bits)
> > + if (dev_priv->psr.busy_frontbuffer_bits || dev_priv
> > ->psr.vlv_src_timing)
> > goto unlock;
>
> I wonder if in this vlv_src_timing case the work should re-schedule
> itself... otherwise we have the risk of psr staying disabled forever
> right?
>
>
intel_psr_work gets rescheduled when vblanks are disabled in
vlv_psr_src_timing_get
> >
> > intel_psr_activate(intel_dp);
> > @@ -708,6 +711,62 @@ void intel_psr_single_frame_update(struct
> > drm_device *dev,
> > }
> >
> > /**
> > + * vlv_psr_src_timing_get - src timing generation requested
> > + *
> > + * CHV does not have HW tracking to trigger PSR exit when VBI are
> > enabled nor
> > + * does enabling vblank interrupts prevent PSR entry. This function
> > is called
> > + * before enabling VBI to exit PSR and prevent PSR re-entry until
> > vblanks are
> > + * disabled again.
> > + */
> > +void vlv_psr_src_timing_get(struct drm_device *dev)
> > +{
> > + struct drm_i915_private *dev_priv = dev->dev_private;
> > +
> > + mutex_lock(&dev_priv->psr.lock);
> > + if (!dev_priv->psr.enabled) {
> > + mutex_unlock(&dev_priv->psr.lock);
> > + return;
> > + }
> > +
> > + //Handle racing with intel_psr_work with this flag
>
> Is this comment permanent? if so you should use /**/
>
I will fix this and send a new version.
> > + dev_priv->psr.vlv_src_timing = true;
> > +
> > + if(dev_priv->psr.active)
> > + intel_psr_exit(dev);
> > +
> > + mutex_unlock(&dev_priv->psr.lock);
> > +
> > +}
> > +
> > +
> > +/**
> > + * vlv_psr_src_timing_put - src timing generation not required
> > + *
> > + * CHV does not have HW tracking to trigger PSR exit when VBI are
> > enabled nor
> > + * does enabling vblank interrupts prevent PSR entry. This function
> > is called
> > + * when VBI are not required and PSR can be activated.
> > + */
> > +void vlv_psr_src_timing_put(struct drm_device *dev)
> > +{
> > + struct drm_i915_private *dev_priv = dev->dev_private;
> > +
> > + mutex_lock(&dev_priv->psr.lock);
> > + if (!dev_priv->psr.enabled) {
> > + mutex_unlock(&dev_priv->psr.lock);
> > + return;
> > + }
> > +
> > + dev_priv->psr.vlv_src_timing = false;
> > +
> > + if (!dev_priv->psr.active)
> > + if (!work_busy(&dev_priv->psr.work.work))
> > + schedule_delayed_work(&dev_priv->psr.work,
> > +
> > msecs_to_jiffies(100));
> > +
> > + mutex_unlock(&dev_priv->psr.lock);
> > +}
> > +
> > +/**
> > * intel_psr_invalidate - Invalidade PSR
> > * @dev: DRM device
> > * @frontbuffer_bits: frontbuffer plane tracking bits
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