[Intel-gfx] [PATCH v4 3/6] drm/i915: prepare pipe for YCBCR420 output

Imre Deak imre.deak at intel.com
Tue Jul 18 19:41:50 UTC 2017


On Wed, Jul 19, 2017 at 12:46:37AM +0530, Sharma, Shashank wrote:
> Regards
> 
> Shashank
> 
> 
> On 7/18/2017 11:42 PM, Imre Deak wrote:
> > On Mon, Jul 17, 2017 at 08:06:24PM +0530, Shashank Sharma wrote:
> > > To get HDMI YCBCR420 output, the PIPEMISC register should be
> > > programmed to:
> > > - Generate YCBCR output (bit 11)
> > > - In case of YCBCR420 outputs, it should be programmed in full
> > >    blend mode to use the scaler in 5x3 ratio (bits 26 and 27)
> > > 
> > > This patch:
> > > - Adds definition of these bits.
> > > - Programs PIPEMISC for YCBCR420 outputs.
> > > - Adds readouts to compare HW and SW states.
> > > 
> > > V2: rebase
> > > V3: rebase
> > > V4: rebase
> > > V5: added r-b from Ander
> > > V6: Handle only YCBCR420 outputs (ville)
> > > V7: rebase
> > > V8: Addressed review comments from Ville
> > >      - Add readouts for state->ycbcr420 and 420 pixel_clock.
> > >      - Handle warning due to mismatch in clock for ycbcr420 clock.
> > >      - Rename PIPEMISC macros to match the Bspec.
> > >      - Add a debug print stating if YCBCR 4:2:0 output enabled.
> > >      Added r-b from Ville
> > > 
> > > Cc: Ville Syrjala <ville.syrjala at linux.intel.com>
> > > Cc: Ander Conselvan de Oliveira <conselvan2 at gmail.com>
> > > Cc: Daniel Vetter <daniel.vetter at intel.com>
> > > 
> > > Reviewed-by: Ander Conselvan de Oliveira <conselvan2 at gmail.com>
> > > Reviewed-by: Ville Syrjala <ville.syrjala at linux.intel.com>
> > > Signed-off-by: Shashank Sharma <shashank.sharma at intel.com>
> > > ---
> > >   drivers/gpu/drm/i915/i915_reg.h      |  3 ++
> > >   drivers/gpu/drm/i915/intel_display.c | 55 ++++++++++++++++++++++++++++++++++--
> > >   2 files changed, 55 insertions(+), 3 deletions(-)
> > > 
> > > diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
> > > index c712d01..6dfcdd3 100644
> > > --- a/drivers/gpu/drm/i915/i915_reg.h
> > > +++ b/drivers/gpu/drm/i915/i915_reg.h
> > > @@ -5227,6 +5227,9 @@ enum {
> > >   #define _PIPE_MISC_A			0x70030
> > >   #define _PIPE_MISC_B			0x71030
> > > +#define   PIPEMISC_YUV420_ENABLE	(1<<27)
> > > +#define   PIPEMISC_YUV420_MODE_BLEND	(1<<26)
> > > +#define   PIPEMISC_OUTPUT_YUV		(1<<11)
> > Missing the rename here requested by Ville.
> Ah, I thought it was more strict on changing YCBCR->YUV, will get this done.
> > >   #define   PIPEMISC_DITHER_BPC_MASK	(7<<5)
> > >   #define   PIPEMISC_DITHER_8_BPC		(0<<5)
> > >   #define   PIPEMISC_DITHER_10_BPC	(1<<5)
> > > diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
> > > index d78f1c2..788502a 100644
> > > --- a/drivers/gpu/drm/i915/intel_display.c
> > > +++ b/drivers/gpu/drm/i915/intel_display.c
> > > @@ -6216,7 +6216,6 @@ static uint32_t ilk_pipe_pixel_rate(const struct intel_crtc_state *pipe_config)
> > >   	 * We only use IF-ID interlacing. If we ever use
> > >   	 * PF-ID we'll need to adjust the pixel_rate here.
> > >   	 */
> > > -
> > Extra w/s change.
> Got it.
> > 
> > >   	if (pipe_config->pch_pfit.enabled) {
> > >   		uint64_t pipe_w, pipe_h, pfit_w, pfit_h;
> > >   		uint32_t pfit_size = pipe_config->pch_pfit.size;
> > > @@ -8076,6 +8075,7 @@ static void haswell_set_pipemisc(struct drm_crtc *crtc)
> > >   {
> > >   	struct drm_i915_private *dev_priv = to_i915(crtc->dev);
> > >   	struct intel_crtc *intel_crtc = to_intel_crtc(crtc);
> > > +	struct intel_crtc_state *config = intel_crtc->config;
> > >   	if (IS_BROADWELL(dev_priv) || INTEL_INFO(dev_priv)->gen >= 9) {
> > >   		u32 val = 0;
> > > @@ -8101,6 +8101,12 @@ static void haswell_set_pipemisc(struct drm_crtc *crtc)
> > >   		if (intel_crtc->config->dither)
> > >   			val |= PIPEMISC_DITHER_ENABLE | PIPEMISC_DITHER_TYPE_SP;
> > > +		if (config->ycbcr420) {
> > > +			val |= PIPEMISC_OUTPUT_YUV |
> > > +				PIPEMISC_YUV420_ENABLE |
> > > +				PIPEMISC_YUV420_MODE_BLEND;
> > > +		}
> > > +
> > >   		I915_WRITE(PIPEMISC(intel_crtc->pipe), val);
> > >   	}
> > >   }
> > > @@ -9170,6 +9176,10 @@ static bool haswell_get_pipe_config(struct intel_crtc *crtc,
> > >   		pipe_config->scaler_state.scaler_users &= ~(1 << SKL_CRTC_INDEX);
> > >   	}
> > > +	if (IS_GEMINILAKE(dev_priv))
> > > +		pipe_config->ycbcr420 = I915_READ(PIPEMISC(crtc->pipe)) &
> > > +					PIPEMISC_YUV420_ENABLE;
> > > +
> > >   	power_domain = POWER_DOMAIN_PIPE_PANEL_FITTER(crtc->pipe);
> > >   	if (intel_display_power_get_if_enabled(dev_priv, power_domain)) {
> > >   		power_domain_mask |= BIT_ULL(power_domain);
> > > @@ -11377,6 +11387,9 @@ static void intel_dump_pipe_config(struct intel_crtc *crtc,
> > >   				      pipe_config->fdi_lanes,
> > >   				      &pipe_config->fdi_m_n);
> > > +	if (pipe_config->ycbcr420)
> > > +		DRM_DEBUG_KMS("YCbCr 4:2:0 output enabled\n");
> > > +
> > >   	if (intel_crtc_has_dp_encoder(pipe_config)) {
> > >   		intel_dump_m_n_config(pipe_config, "dp m_n",
> > >   				pipe_config->lane_count, &pipe_config->dp_m_n);
> > > @@ -11704,6 +11717,22 @@ intel_modeset_update_crtc_state(struct drm_atomic_state *state)
> > >   	}
> > >   }
> > > +static bool intel_420_clock_check(int clock1, int clock2)
> > > +{
> > > +	int diff;
> > > +
> > > +	if (clock1 == clock2 * 2)
> > > +		return true;
> > > +
> > > +	clock2 *= 2;
> > > +	diff = abs(clock1 - clock2);
> > > +
> > > +	if (((((diff + clock1 + clock2) * 100)) / (clock1 + clock2)) < 105)
> > > +		return true;
> > > +
> > > +	return false;
> > > +}
> > > +
> > >   static bool intel_fuzzy_clock_check(int clock1, int clock2)
> > >   {
> > >   	int diff;
> > > @@ -11832,6 +11861,18 @@ intel_pipe_config_compare(struct drm_i915_private *dev_priv,
> > >   		ret = false; \
> > >   	}
> > > +#define PIPE_CONF_CHECK_CLOCK_420(name) \
> > > +	do { \
> > > +		if (!intel_420_clock_check(current_config->name, \
> > > +					   pipe_config->name)) { \
> > > +			pipe_config_err(adjust, __stringify(name), \
> > > +				  "(expected %i, found %i)\n", \
> > > +				  current_config->name, \
> > > +				  pipe_config->name); \
> > > +			ret = false; \
> > > +		} \
> > > +	} while (0)
> > > +
> > >   #define PIPE_CONF_CHECK_M_N(name) \
> > >   	if (!intel_compare_link_m_n(&current_config->name, \
> > >   				    &pipe_config->name,\
> > > @@ -11983,7 +12024,10 @@ intel_pipe_config_compare(struct drm_i915_private *dev_priv,
> > >   		}
> > >   		PIPE_CONF_CHECK_I(scaler_state.scaler_id);
> > > -		PIPE_CONF_CHECK_CLOCK_FUZZY(pixel_rate);
> > > +		if (current_config->ycbcr420)
> > > +			PIPE_CONF_CHECK_CLOCK_420(pixel_rate);
> > > +		else
> > > +			PIPE_CONF_CHECK_CLOCK_FUZZY(pixel_rate);
> > >   	}
> > >   	/* BDW+ don't expose a synchronous way to read the state */
> > > @@ -12009,7 +12053,11 @@ intel_pipe_config_compare(struct drm_i915_private *dev_priv,
> > >   	if (IS_G4X(dev_priv) || INTEL_GEN(dev_priv) >= 5)
> > >   		PIPE_CONF_CHECK_I(pipe_bpp);
> > > -	PIPE_CONF_CHECK_CLOCK_FUZZY(base.adjusted_mode.crtc_clock);
> > > +	/* YCBCR 420 pixel clock is half of the actual mode */
> > > +	if (current_config->ycbcr420)
> > > +		PIPE_CONF_CHECK_CLOCK_420(base.adjusted_mode.crtc_clock);
> > > +	else
> > > +		PIPE_CONF_CHECK_CLOCK_FUZZY(base.adjusted_mode.crtc_clock);
> > >   	PIPE_CONF_CHECK_CLOCK_FUZZY(port_clock);
> > >   #undef PIPE_CONF_CHECK_X
> > > @@ -12018,6 +12066,7 @@ intel_pipe_config_compare(struct drm_i915_private *dev_priv,
> > >   #undef PIPE_CONF_CHECK_FLAGS
> > >   #undef PIPE_CONF_CHECK_CLOCK_FUZZY
> > >   #undef PIPE_CONF_QUIRK
> > > +#undef PIPE_CONF_CHECK_CLOCK_420
> > We don't need to adjust things during compare. The dotclock is 2x
> > the port clock in case of YUV420, so all what's needed is
> > 
> > if (pipe_config->ycbcr420)
> > 	dotclock = pipe_config->port_clock * 2;
> > 
> > in ddi_get_clock() as Ville said.
> Got it,
> > Also, right now if I boot with these patches all 4k YUV420 modes will be
> > pruned on my monitor. This is caused by the monitor reporting a 300MHz
> > max tmds clock (which is the port clock limit) and the driver comparing
> > this against the dotclock which is double of this. So I needed
> > 
> > if (drm_mode_is_420_only(&connector->display_info, mode))
> > 	clock /= 2;
> > 
> > in intel_hdmi_mode_valid() to preserve these modes. Not sure why this
> > didn't come up earlier.
> Because, when a monitor declares max clock on 300Mhz, it doesn't contain a
> mode in its EDID which needs clock  > 300Mhz, but YCBCR_420 introduces a
> corner case here, its possible if all the modes with clock > 300Mhz are
> YCBCR420_only modes.

Well, Ville was using the same montior. In any case looks like we just need
the above adjustment in intel_hdmi_mode_valid() then.

> Looks like you got hold of one such monitor, which is HDMI 2.0 but has all
> its 4k at 60 modes as YCBCR420_only, and hence they fit into 300Mhz limit.  In
> any case, its not illegal, and should have been taken care of in code, so
> thanks for pointing this out.
> Can you please share the monitor details ? I will see if I have one here in
> Bangalore.

It's a Samsung monitor with 4096x2160 at 60Hz and 3840x2400 at 60Hz modes. The
dotclock for these is ~600MHz while the portclock is half of this. They
are also YUV420 only modes, so yes, that is where the 300MHz limit comes
from.

> > 
> > With that I see the YUV420 modes, but the initial modeset for the fb
> > console will result in the gray screen and some jitter. A following
> > modeset with the same mode will fix things; this is I think what Ville
> > also saw. Still trying to find the reason for this.
> Can you also please check if this is specific to one particular monitor ? I
> still can't reproduce this issue with my GLK + ACER/SAMSUNG monitors.

Not sure if I have any other monitor with YUV420 formats, I will do some
more debugging tomorrow.

--Imre

> - Shashank
> > 
> > --Imre
> > 
> > >   	return ret;
> > >   }
> > > -- 
> > > 2.7.4
> > > 
> 


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