Re: [CI 15/19] drm/i915/bigjoiner: atomic commit changes for uncompressed joiner

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 




> -----Original Message-----
> From: Jani Nikula <jani.nikula@xxxxxxxxxxxxxxx>
> Sent: Thursday, June 3, 2021 6:03 PM
> To: Roper, Matthew D <matthew.d.roper@xxxxxxxxx>; intel-
> gfx@xxxxxxxxxxxxxxxxxxxxx
> Cc: Manna, Animesh <animesh.manna@xxxxxxxxx>; Navare, Manasi D
> <manasi.d.navare@xxxxxxxxx>; Kulkarni, Vandita <vandita.kulkarni@xxxxxxxxx>
> Subject: Re:  [CI 15/19] drm/i915/bigjoiner: atomic commit changes
> for uncompressed joiner
> 
> On Thu, 03 Jun 2021, Jani Nikula <jani.nikula@xxxxxxxxxxxxxxx> wrote:
> > On Fri, 14 May 2021, Matt Roper <matthew.d.roper@xxxxxxxxx> wrote:
> >> From: Animesh Manna <animesh.manna@xxxxxxxxx>
> >>
> >> Respective bit for master or slave to be set for uncompressed
> >> bigjoiner in dss_ctl1 register.
> >
> > I was looking at the changes here due to a static checker complaint,
> > and I think there are a number of issues here. Some more serious than
> > others, and some predate the patch.
> >
> > Comments inline.
> >
> >> Cc: Manasi Navare <manasi.d.navare@xxxxxxxxx>
> >> Signed-off-by: Animesh Manna <animesh.manna@xxxxxxxxx>
> >> Signed-off-by: Clinton Taylor <Clinton.A.Taylor@xxxxxxxxx>
> >> Signed-off-by: Matt Roper <matthew.d.roper@xxxxxxxxx>
> >> Reviewed-by: Manasi Navare <manasi.d.navare@xxxxxxxxx>
> >> ---
> >>  drivers/gpu/drm/i915/display/intel_display.c |  6 +++
> >>  drivers/gpu/drm/i915/display/intel_vdsc.c    | 40 +++++++++++++++++++-
> >>  drivers/gpu/drm/i915/display/intel_vdsc.h    |  2 +
> >>  drivers/gpu/drm/i915/i915_reg.h              |  2 +
> >>  4 files changed, 49 insertions(+), 1 deletion(-)
> >>
> >> diff --git a/drivers/gpu/drm/i915/display/intel_display.c
> >> b/drivers/gpu/drm/i915/display/intel_display.c
> >> index b5fd721137d3..422b59ebf6dc 100644
> >> --- a/drivers/gpu/drm/i915/display/intel_display.c
> >> +++ b/drivers/gpu/drm/i915/display/intel_display.c
> >> @@ -3411,6 +3411,7 @@ static void icl_ddi_bigjoiner_pre_enable(struct
> intel_atomic_state *state,
> >>  					 const struct intel_crtc_state
> *crtc_state)  {
> >>  	struct intel_crtc *master = to_intel_crtc(crtc_state->uapi.crtc);
> >> +	struct drm_i915_private *dev_priv = to_i915(master->base.dev);
> >>  	struct intel_crtc_state *master_crtc_state;
> >>  	struct drm_connector_state *conn_state;
> >>  	struct drm_connector *conn;
> >> @@ -3444,6 +3445,9 @@ static void icl_ddi_bigjoiner_pre_enable(struct
> intel_atomic_state *state,
> >>  		/* and DSC on slave */
> >>  		intel_dsc_enable(NULL, crtc_state);
> >>  	}
> >> +
> >> +	if (DISPLAY_VER(dev_priv) >= 13)
> 
> I don't think we should add these checks here. Make sure the crtc_state only has
> the relevant stuff enabled if the platform supports it. Don't duplicate the checks.

Agree.

> 
> >> +		intel_uncompressed_joiner_enable(crtc_state);
> 
> As this is always called after intel_dsc_enable(), I think it would make sense to
> move this within intel_dsc_enable().

Agree.
> 
> >>  }
> >>
> >>  static void hsw_crtc_enable(struct intel_atomic_state *state, @@
> >> -6250,6 +6254,8 @@ static bool hsw_get_pipe_config(struct intel_crtc *crtc,
> >>  	}
> >>
> >>  	intel_dsc_get_config(pipe_config);
> >> +	if (DISPLAY_VER(dev_priv) >= 13 && !pipe_config-
> >dsc.compression_enable)
> >> +		intel_uncompressed_joiner_get_config(pipe_config);
> 
> As this is always called after intel_dsc_get_config(), I think it would make sense
> to move this within intel_dsc_get_config.
> 
> >>
> >>  	if (!active) {
> >>  		/* bigjoiner slave doesn't enable transcoder */ diff --git
> >> a/drivers/gpu/drm/i915/display/intel_vdsc.c
> >> b/drivers/gpu/drm/i915/display/intel_vdsc.c
> >> index adcd6752f919..efc3184d8315 100644
> >> --- a/drivers/gpu/drm/i915/display/intel_vdsc.c
> >> +++ b/drivers/gpu/drm/i915/display/intel_vdsc.c
> >> @@ -1021,6 +1021,22 @@ static i915_reg_t dss_ctl2_reg(const struct
> intel_crtc_state *crtc_state)
> >>  	return is_pipe_dsc(crtc_state) ? ICL_PIPE_DSS_CTL2(pipe) :
> >> DSS_CTL2;  }
> >>
> >> +void intel_uncompressed_joiner_enable(const struct intel_crtc_state
> >> +*crtc_state)
> >
> > Naming. Basically for any new function, the function name prefix
> > should match the file name. intel_vdsc.[ch] should have functions
> > prefixed intel_vdsc_*(). This is where we're headed to increase clarity.
> >
> > intel_uncompressed_*() is something completely different.
> >
> > Granted, here we already have intel_dsc_*() in intel_vdsc.c. We should
> > probably stick with intel_dsc_*(). A possible function or file rename
> > is not out of the question, but that's a separate matter.
> >
> >> +{
> >> +	struct intel_crtc *crtc = to_intel_crtc(crtc_state->uapi.crtc);
> >> +	struct drm_i915_private *dev_priv = to_i915(crtc->base.dev);
> >> +	u32 dss_ctl1_val = 0;
> >> +
> >> +	if (crtc_state->bigjoiner && !crtc_state->dsc.compression_enable) {
> >> +		if (crtc_state->bigjoiner_slave)
> >> +			dss_ctl1_val |= UNCOMPRESSED_JOINER_SLAVE;
> >> +		else
> >> +			dss_ctl1_val |= UNCOMPRESSED_JOINER_MASTER;
> >> +
> >> +		intel_de_write(dev_priv, dss_ctl1_reg(crtc_state), dss_ctl1_val);
> >> +	}
> >> +}
> >> +
> >>  void intel_dsc_enable(struct intel_encoder *encoder,
> >>  		      const struct intel_crtc_state *crtc_state)  { @@ -1060,13
> >> +1076,35 @@ void intel_dsc_disable(const struct intel_crtc_state
> *old_crtc_state)
> >>  	struct intel_crtc *crtc = to_intel_crtc(old_crtc_state->uapi.crtc);
> >>  	struct drm_i915_private *dev_priv = to_i915(crtc->base.dev);
> >>
> >> -	if (!old_crtc_state->dsc.compression_enable)
> >> +	if (!(old_crtc_state->dsc.compression_enable &&
> >> +	      old_crtc_state->bigjoiner))
> >
> > This fails to disable compression if we only have compression but no
> > bigjoiner, which is the more common case!
> >
> > See also:
> >
> > https://gitlab.freedesktop.org/drm/intel/-/issues/3537
> > https://patchwork.freedesktop.org/patch/msgid/20210603065356.15435-1-v
> > andita.kulkarni@xxxxxxxxx
> >
> >>  		return;
> >>
> >>  	intel_de_write(dev_priv, dss_ctl1_reg(old_crtc_state), 0);
> >>  	intel_de_write(dev_priv, dss_ctl2_reg(old_crtc_state), 0);  }
> >>
> >> +void intel_uncompressed_joiner_get_config(struct intel_crtc_state
> >> +*crtc_state) {
> >> +	struct intel_crtc *crtc = to_intel_crtc(crtc_state->uapi.crtc);
> >> +	struct drm_i915_private *dev_priv = to_i915(crtc->base.dev);
> >> +	u32 dss_ctl1;
> >> +
> >> +	dss_ctl1 = intel_de_read(dev_priv, dss_ctl1_reg(crtc_state));
> 
> You can't read this without holding the power domain.
> 
> Since this is always called after intel_dsc_get_config(), I think it would make
> sense to move this reading there.

Ok.
Earlier the plan is to have separate functions for uncompressed joiner, but as you suggested it can be done in the same functions of compressed bigjoiner code.
Thanks Jani for review.

Regards,
Animesh

> 
> >> +	if (dss_ctl1 & UNCOMPRESSED_JOINER_MASTER) {
> >> +		crtc_state->bigjoiner = true;
> >> +		if (!WARN_ON(INTEL_NUM_PIPES(dev_priv) == crtc->pipe + 1))
> >> +			crtc_state->bigjoiner_linked_crtc =
> >> +				intel_get_crtc_for_pipe(dev_priv, crtc->pipe +
> 1);
> >> +	} else if (dss_ctl1 & UNCOMPRESSED_JOINER_SLAVE) {
> >> +		crtc_state->bigjoiner = true;
> >> +		crtc_state->bigjoiner_slave = true;
> >> +		if (!WARN_ON(crtc->pipe == PIPE_A))
> >> +			crtc_state->bigjoiner_linked_crtc =
> >> +				intel_get_crtc_for_pipe(dev_priv, crtc->pipe -
> 1);
> >> +	}
> >
> > Nitpick: This duplicates a bunch of logic for figuring out master/slave.
> >
> > The static checker warning was about crtc->pipe + 1 usage. Since
> > INTEL_NUM_PIPES() looks at the hamming weight of i915->pipe_mask, the
> > checker has a hard time figuring out it does not overflow
> > i915->pipe_to_crtc_mapping[] in intel_get_crtc_for_pipe().
> >
> > So here in intel_vdsc.c the checks are for overflowing/underflowing
> > the pipe range. In intel_get_crtc_for_pipe() there's a check for the
> > pipe actually existing - the pipe numbering might not be contiguous.
> >
> > Superficially the static checker warning is bogus, as in we won't
> > overflow anything. However, deep down there are issues in the
> > consistency of the checks and how to handle non-contigouous pipe
> > numbering.
> >
> > Indeed, this does not *need* the number. We should figure out the next
> > *crtc*, not the next pipe *number*, which may or may not be pipe + 1.
> >
> >
> > BR,
> > Jani.
> >
> >> +}
> >> +
> >>  void intel_dsc_get_config(struct intel_crtc_state *crtc_state)  {
> >>  	struct drm_dsc_config *vdsc_cfg = &crtc_state->dsc.config; diff
> >> --git a/drivers/gpu/drm/i915/display/intel_vdsc.h
> >> b/drivers/gpu/drm/i915/display/intel_vdsc.h
> >> index 65d301c23580..fe4d45561253 100644
> >> --- a/drivers/gpu/drm/i915/display/intel_vdsc.h
> >> +++ b/drivers/gpu/drm/i915/display/intel_vdsc.h
> >> @@ -12,11 +12,13 @@ struct intel_encoder;  struct intel_crtc_state;
> >>
> >>  bool intel_dsc_source_support(const struct intel_crtc_state
> >> *crtc_state);
> >> +void intel_uncompressed_joiner_enable(const struct intel_crtc_state
> >> +*crtc_state);
> >>  void intel_dsc_enable(struct intel_encoder *encoder,
> >>  		      const struct intel_crtc_state *crtc_state);  void
> >> intel_dsc_disable(const struct intel_crtc_state *crtc_state);  int
> >> intel_dsc_compute_params(struct intel_encoder *encoder,
> >>  			     struct intel_crtc_state *pipe_config);
> >> +void intel_uncompressed_joiner_get_config(struct intel_crtc_state
> >> +*crtc_state);
> >>  void intel_dsc_get_config(struct intel_crtc_state *crtc_state);
> >> enum intel_display_power_domain  intel_dsc_power_domain(const struct
> >> intel_crtc_state *crtc_state); diff --git
> >> a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
> >> index 31bc413dbba1..dd6e0bae9573 100644
> >> --- a/drivers/gpu/drm/i915/i915_reg.h
> >> +++ b/drivers/gpu/drm/i915/i915_reg.h
> >> @@ -11493,6 +11493,8 @@ enum skl_power_gate {
> >>  #define  SPLITTER_CONFIGURATION_MASK		REG_GENMASK(26, 25)
> >>  #define  SPLITTER_CONFIGURATION_2_SEGMENT
> 	REG_FIELD_PREP(SPLITTER_CONFIGURATION_MASK, 0)
> >>  #define  SPLITTER_CONFIGURATION_4_SEGMENT
> 	REG_FIELD_PREP(SPLITTER_CONFIGURATION_MASK, 1)
> >> +#define  UNCOMPRESSED_JOINER_MASTER		(1 << 21)
> >> +#define  UNCOMPRESSED_JOINER_SLAVE		(1 << 20)
> >>
> >>  #define _ICL_PIPE_DSS_CTL2_PB			0x78204
> >>  #define _ICL_PIPE_DSS_CTL2_PC			0x78404
> 
> --
> Jani Nikula, Intel Open Source Graphics Center
_______________________________________________
Intel-gfx mailing list
Intel-gfx@xxxxxxxxxxxxxxxxxxxxx
https://lists.freedesktop.org/mailman/listinfo/intel-gfx



[Index of Archives]     [AMD Graphics]     [Linux USB Devel]     [Linux Audio Users]     [Yosemite News]     [Linux Kernel]     [Linux SCSI]

  Powered by Linux