[Intel-gfx] [PATCH 2/4] drm/i915: Disable PSR2 while getting pipe CRC
Souza, Jose
jose.souza at intel.com
Sat Feb 16 00:20:32 UTC 2019
On Fri, 2019-02-15 at 00:17 +0000, Souza, Jose wrote:
> On Thu, 2019-02-14 at 16:10 -0800, Pandiyan, Dhinakaran wrote:
> > On Thu, 2019-02-14 at 15:19 -0800, Souza, Jose wrote:
> > > On Thu, 2019-02-14 at 11:00 -0800, Dhinakaran Pandiyan wrote:
> > > > On Wed, 2019-02-13 at 18:02 -0800, José Roberto de Souza wrote:
> > > > > As stated in CRC_CTL spec, after PSR entry state CRC will not
> > > > > be
> > > > > calculated anymore what is not a problem as IGT tests do some
> > > > > screen
> > > > > change and then request the pipe CRC right after the change
> > > > > so
> > > > > PSR
> > > > > will go to idle state and only will entry again after at
> > > > > least
> > > > > 6
> > > > > idles frames.
> > > > >
> > > > > But for PSR2 it is more problematic as any change to the
> > > > > screen
> > > > > could
> > > > > trigger a selective/partial update causing the CRC value not
> > > > > to
> > > > > be
> > > > > calculated over the full frame.
> > > >
> > > > Okay, that reasoning runs counter to my understanding. My
> > > > understanding
> > > > is that the whole frame is fetched and processed at the pipe
> > > > level
> > > > but
> > > > the DDI sends selective blocks of pixels. So, if the CRC's are
> > > > calculated at the pipe level, the CRC should be for the full
> > > > frame
> > > > with
> > > > PSR2 having no effect? Checking bspec, I see there are DDI CRCs
> > > > as
> > > > well, which should reflect the partial frame that PSR2 sends.
> > > >
> > > > To get a better understanding, I'd like to know what the source
> > > > for
> > > > mismatching CRCs is?
> > >
> > > Well the naming is misleading for newer gens, before BDW this was
> > > a
> > > pipe register(8067) but now it is a DDI register(7536) but the
> > > register
> > > offset was kept the same.
> > Do we even read this register DDI_CRC_CTL? Don't see it defined in
> > i915_reg.h or referenced in intel_pipe_crc.c.
>
> We do: PIPE_CRC_CTL().
> #define _PIPE_CRC_CTL_A 0x60050
I was wrong, the first CRC generated is wrong but it is not read by
userspace as we skip it using pipe_crc->skipped it is docummented in
the code too.
The problem here is that after PSR2 is activated(after 'Frames Before
SU Entry') there is no more CRC interruptions so no calls to
drm_crtc_add_crc_entry(), what don't happen with PSR1 even setting a
'Idle Frames' to 1.
Other odd thing that I discovered it that we have CRC_CTL register in
DDI(Bspec 7536) and other in PIPE(Bspec 7646) with diferent bits and we
write in the transcoder offset using the pipe bits. I tried to use the
PIPE offset but it do not generate any interruption, anyone know more
about that?
>
> > > In my testing hardware generate 4 interruptions with wrong CRC
> > > values
> > > then stops forever probably because vblank interruptions are off.
> > Yeah, my guess is that power management is affecting the CRC
> > generation
> > rather than pipe CRC's being calculated only on the SU update
> > blocks.
> >
> >
> > > > > So here it disables PSR2 and keep it disabled while user is
> > > > > requesting pipe CRC.
> > > > >
> > > > > BSpec: 7536
> > > > >
> > > > > Cc: Dhinakaran Pandiyan <dhinakaran.pandiyan at intel.com>
> > > > > Cc: Ville Syrjälä <ville.syrjala at linux.intel.com>
> > > > > Signed-off-by: José Roberto de Souza <jose.souza at intel.com>
> > > > > ---
> > > > > drivers/gpu/drm/i915/i915_drv.h | 1 +
> > > > > drivers/gpu/drm/i915/intel_drv.h | 1 +
> > > > > drivers/gpu/drm/i915/intel_pipe_crc.c | 10 ++++++++++
> > > > > drivers/gpu/drm/i915/intel_psr.c | 23
> > > > > +++++++++++++++++++++++
> > > > > 4 files changed, 35 insertions(+)
> > > > >
> > > > > diff --git a/drivers/gpu/drm/i915/i915_drv.h
> > > > > b/drivers/gpu/drm/i915/i915_drv.h
> > > > > index 17fe942eaafa..609e9c5bd453 100644
> > > > > --- a/drivers/gpu/drm/i915/i915_drv.h
> > > > > +++ b/drivers/gpu/drm/i915/i915_drv.h
> > > > > @@ -520,6 +520,7 @@ struct i915_psr {
> > > > > bool sink_not_reliable;
> > > > > bool irq_aux_error;
> > > > > u16 su_x_granularity;
> > > > > + bool pipe_crc_enabled;
> > > > > };
> > > > >
> > > > > enum intel_pch {
> > > > > diff --git a/drivers/gpu/drm/i915/intel_drv.h
> > > > > b/drivers/gpu/drm/i915/intel_drv.h
> > > > > index 3398b28c053b..40ce7a600585 100644
> > > > > --- a/drivers/gpu/drm/i915/intel_drv.h
> > > > > +++ b/drivers/gpu/drm/i915/intel_drv.h
> > > > > @@ -2103,6 +2103,7 @@ void intel_psr_short_pulse(struct
> > > > > intel_dp
> > > > > *intel_dp);
> > > > > int intel_psr_wait_for_idle(const struct intel_crtc_state
> > > > > *new_crtc_state,
> > > > > u32 *out_value);
> > > > > bool intel_psr_enabled(struct intel_dp *intel_dp);
> > > > > +void intel_psr_crc_prepare_or_finish(struct drm_i915_private
> > > > > *dev_priv, enum pipe pipe, bool prepare);
> > > > >
> > > > > /* intel_quirks.c */
> > > > > void intel_init_quirks(struct drm_i915_private *dev_priv);
> > > > > diff --git a/drivers/gpu/drm/i915/intel_pipe_crc.c
> > > > > b/drivers/gpu/drm/i915/intel_pipe_crc.c
> > > > > index a8554dc4f196..5d8772399f60 100644
> > > > > --- a/drivers/gpu/drm/i915/intel_pipe_crc.c
> > > > > +++ b/drivers/gpu/drm/i915/intel_pipe_crc.c
> > > > > @@ -583,6 +583,14 @@ int intel_crtc_verify_crc_source(struct
> > > > > drm_crtc
> > > > > *crtc, const char *source_name,
> > > > > return -EINVAL;
> > > > > }
> > > > >
> > > > > +static inline void intel_crtc_crc_prepare_or_finish(struct
> > > > > drm_crtc
> > > > > *crtc, bool prepare)
> > > > > +{
> > > > > + struct drm_i915_private *dev_priv = to_i915(crtc->dev);
> > > > > + struct intel_crtc *intel_crtc = to_intel_crtc(crtc);
> > > > > +
> > > > > + intel_psr_crc_prepare_or_finish(dev_priv, intel_crtc-
> > > > > > pipe,
> > > > > prepare);
> > > > > +}
> > > > > +
> > > > > int intel_crtc_set_crc_source(struct drm_crtc *crtc, const
> > > > > char
> > > > > *source_name)
> > > > > {
> > > > > struct drm_i915_private *dev_priv = to_i915(crtc->dev);
> > > > > @@ -609,6 +617,8 @@ int intel_crtc_set_crc_source(struct
> > > > > drm_crtc
> > > > > *crtc, const char *source_name)
> > > > > if (ret != 0)
> > > > > goto out;
> > > > >
> > > > > + intel_crtc_crc_prepare_or_finish(crtc, source !=
> > > > > INTEL_PIPE_CRC_SOURCE_NONE);
> > > > > +
> > > > > pipe_crc->source = source;
> > > > > I915_WRITE(PIPE_CRC_CTL(crtc->index), val);
> > > > > POSTING_READ(PIPE_CRC_CTL(crtc->index));
> > > > > diff --git a/drivers/gpu/drm/i915/intel_psr.c
> > > > > b/drivers/gpu/drm/i915/intel_psr.c
> > > > > index 08967836b48e..9c93138988aa 100644
> > > > > --- a/drivers/gpu/drm/i915/intel_psr.c
> > > > > +++ b/drivers/gpu/drm/i915/intel_psr.c
> > > > > @@ -577,6 +577,9 @@ static bool
> > > > > intel_psr2_config_valid(struct
> > > > > intel_dp *intel_dp,
> > > > > return false;
> > > > > }
> > > > >
> > > > > + if (dev_priv->psr.pipe_crc_enabled)
> > > > > + return false;
> > > > > +
> > > > > return true;
> > > > > }
> > > > >
> > > > > @@ -1291,3 +1294,23 @@ bool intel_psr_enabled(struct intel_dp
> > > > > *intel_dp)
> > > > >
> > > > > return ret;
> > > > > }
> > > > > +
> > > > > +void intel_psr_crc_prepare_or_finish(struct drm_i915_private
> > > > > *dev_priv, enum pipe pipe, bool prepare)
> > > > > +{
> > > > > + bool fastset = false;
> > > > > +
> > > > > + if (!CAN_PSR(dev_priv))
> > > > > + return;
> > > > > +
> > > > > + mutex_lock(&dev_priv->psr.lock);
> > > > > +
> > > > > + if (dev_priv->psr.pipe == pipe) {
> > > > > + dev_priv->psr.pipe_crc_enabled = prepare;
> > > > > + fastset = !prepare || dev_priv-
> > > > > > psr.psr2_enabled;
> > > > > + }
> > > > > +
> > > > > + mutex_unlock(&dev_priv->psr.lock);
> > > > > +
> > > > > + if (fastset)
> > > > > + intel_psr_fastset_force(dev_priv);
> > > > > +}
>
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