Re: [PATCH] [RFC] drm/i915/skl+: enable PF_ID interlace mode in SKL

["Ville Syrjälä" <ville.syrjala@linux.intel.com>]

On Mon, Jun 19, 2017 at 05:50:28PM +0530, Mahesh Kumar wrote:
> Hi Ville,
> 
> Thanks for review
> 
> 
> On Friday 16 June 2017 07:47 PM, Ville Syrjälä wrote:
> > On Wed, Jun 07, 2017 at 03:19:05PM +0530, Mahesh Kumar wrote:
> >> In previous GEN default Interlace mode enabled is IF-ID mode, but IF-ID
> >> mode has many limitations in SKL. This mode doesn't support y-tiling,
> >> 90-270 rotation is not supported & YUV-420 planar source pixel formats
> >> are not supported with above mode.
> > I think we'll want something much more simple for stable. And that
> > should probably be just -EINVAL if we try to do any of those
> > forbidden things with an interlaced mode.
> Agree.
> >
> >> This patch make changes to use PF-ID Interlace mode in SKL+ platforms.
> >> PF-ID mode require one scaler to be attached in pipe-scaling mode.
> >>    During WM calculation adjusted pixel rate need to be doubled.
> >>    During max_supported_pixel_format calculation vertical downscale is 2.0.
> >>
> >> Signed-off-by: Mahesh Kumar <mahesh1.kumar@intel.com>
> >> Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=90238
> >> ---
> >>   drivers/gpu/drm/i915/intel_atomic.c  | 13 ++++++++++
> >>   drivers/gpu/drm/i915/intel_display.c | 47 +++++++++++++++++++++++++++++++-----
> >>   drivers/gpu/drm/i915/intel_drv.h     | 10 ++++++++
> >>   drivers/gpu/drm/i915/intel_panel.c   |  9 +++++--
> >>   drivers/gpu/drm/i915/intel_pm.c      | 17 ++++++++++++-
> >>   5 files changed, 87 insertions(+), 9 deletions(-)
> >>
> >> diff --git a/drivers/gpu/drm/i915/intel_atomic.c b/drivers/gpu/drm/i915/intel_atomic.c
> >> index d791b3ef89b5..06ed2fc449d7 100644
> >> --- a/drivers/gpu/drm/i915/intel_atomic.c
> >> +++ b/drivers/gpu/drm/i915/intel_atomic.c
> >> @@ -248,6 +248,13 @@ int intel_atomic_setup_scalers(struct drm_i915_private *dev_priv,
> >>   		return -EINVAL;
> >>   	}
> >>   
> >> +	if (num_scalers_need > 1 &&
> >> +			scaler_state->scaler_users & (1 << SKL_CRTC_INDEX) &&
> >> +			scaler_state->scaler_users & (1 << SKL_PF_ID_INDEX)) {
> >> +		DRM_ERROR("Can't attach scaler to CRTC in Interlace Mode\n");
> >> +		return -EINVAL;
> >> +	}
> > I thought the whole point of PF-ID here was that we can then do pipe
> > scaling (and other things). So this check looks wrong to me.
> With PF-ID we can have Y-tiled buffers, & 90/270 rotation enabled, It 
> doesn't explicitly talk about scaling.

PF-ID itself is scaling. Presumably you don't have to have exactly
2:1 scaling factor with PF-ID.

> BSpec doesn't limit us from using 2 scalers as a pipe scaler, still I 
> sent a query to HW team regarding same.

We don't want to use multiple scalers. I dubt that would even work. And
before SKL the panel fitter was a dedicated piece of hw anyway so there
was no way to even try to assign multiple scalers to the pipe.

>
> Current S/W framework doesn't allows us to attach multiple pipe-scalers 
> in a pipe (multiple scaler_id associated with one crtc_state). that's 
> the reason for above check.
> >
> > And I'm thinking we shouldn't be adding yet another scaler user for
> > this, and instead it should just be part of the normal pfit setup.
> To use existing scaler framework, we need one scaler-user to be 
> associated with it.
> If we use existing CRTC_INDEX user then there will be many corner cases 
> to handle.

I'm not 100% whether we need any adjustment in the pfit code itself.
The spec doesn't seem to tell us that we need to adjust the panel
fitter window in any way. That's a little inconsistent with the
resulting scaling factor, but I guess the hw will automagically reduce
the destination size by two when the pipe is in the PF-ID mode.

So I think it should mostly be a simple matter of calling the pfit
code to set up the pos/size, and then you should just adjust
ilk_pipe_pixel_rate() to double the resulting pixel rate.

That said, I'm not really sure we want to flip PF-ID on automagically.
It would result in scaling when the user doesn't necessarily want it.
So we might want to think about some kind if property to control this
stuff.

> To make it simple I added new scaler-user.
> This code uses pfit setup only  to attach/enable Pipe-scaler.
> Please let me know if I didn't understood your concern correctly.
> Any other suggestions/queries are welcome.
> 
> -Mahesh
> 
> >
> >> +
> >>   	/* walkthrough scaler_users bits and start assigning scalers */
> >>   	for (i = 0; i < sizeof(scaler_state->scaler_users) * 8; i++) {
> >>   		int *scaler_id;
> >> @@ -264,6 +271,12 @@ int intel_atomic_setup_scalers(struct drm_i915_private *dev_priv,
> >>   
> >>   			/* panel fitter case: assign as a crtc scaler */
> >>   			scaler_id = &scaler_state->scaler_id;
> >> +		} else if (i == SKL_PF_ID_INDEX) {
> >> +			name = "PF-ID INTERLACE MODE";
> >> +			idx = intel_crtc->base.base.id;
> >> +
> >> +			/* PF-ID interlaced mode case: needs a pipe scaler */
> >> +			scaler_id = &scaler_state->scaler_id;
> >>   		} else {
> >>   			name = "PLANE";
> >>   
> >> diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
> >> index 85ac32549e85..15c79b46d645 100644
> >> --- a/drivers/gpu/drm/i915/intel_display.c
> >> +++ b/drivers/gpu/drm/i915/intel_display.c
> >> @@ -4626,6 +4626,11 @@ skl_update_scaler(struct intel_crtc_state *crtc_state, bool force_detach,
> >>   	 */
> >>   	need_scaling = src_w != dst_w || src_h != dst_h;
> >>   
> >> +	if ((crtc_state->base.adjusted_mode.flags & DRM_MODE_FLAG_INTERLACE)
> >> +		&& scaler_user == SKL_PF_ID_INDEX)
> >> +		/* PF-ID Interlace mode needs a scaler */
> >> +		need_scaling = true;
> >> +
> >>   	/*
> >>   	 * if plane is being disabled or scaler is no more required or force detach
> >>   	 *  - free scaler binded to this plane/crtc
> >> @@ -4635,16 +4640,24 @@ skl_update_scaler(struct intel_crtc_state *crtc_state, bool force_detach,
> >>   	 * scaler can be assigned to other user. Actual register
> >>   	 * update to free the scaler is done in plane/panel-fit programming.
> >>   	 * For this purpose crtc/plane_state->scaler_id isn't reset here.
> >> +	 * Now Interlace mode is a new user of pipe-scaler, so free the scaler-id
> >> +	 * only if call is for respective user. If no user for scaler free it.
> >>   	 */
> >>   	if (force_detach || !need_scaling) {
> >> -		if (*scaler_id >= 0) {
> >> +		if (*scaler_id >= 0 &&
> >> +		    scaler_state->scaler_users & (1 << scaler_user)) {
> >>   			scaler_state->scaler_users &= ~(1 << scaler_user);
> >>   			scaler_state->scalers[*scaler_id].in_use = 0;
> >>   
> >>   			DRM_DEBUG_KMS("scaler_user index %u.%u: "
> >>   				"Staged freeing scaler id %d scaler_users = 0x%x\n",
> >> -				intel_crtc->pipe, scaler_user, *scaler_id,
> >> -				scaler_state->scaler_users);
> >> +				intel_crtc->pipe, scaler_user,
> >> +				*scaler_id, scaler_state->scaler_users);
> >> +
> >> +			*scaler_id = -1;
> >> +		}
> >> +		if (*scaler_id >= 0 && !scaler_state->scaler_users) {
> >> +			scaler_state->scalers[*scaler_id].in_use = 0;
> >>   			*scaler_id = -1;
> >>   		}
> >>   		return 0;
> >> @@ -4691,6 +4704,16 @@ int skl_update_scaler_crtc(struct intel_crtc_state *state)
> >>   		adjusted_mode->crtc_hdisplay, adjusted_mode->crtc_vdisplay);
> >>   }
> >>   
> >> +static int skl_update_scaler_crtc_pf_id_output(struct intel_crtc_state *state)
> >> +{
> >> +	const struct drm_display_mode *mode = &state->base.adjusted_mode;
> >> +
> >> +	return skl_update_scaler(state, !state->base.active,
> >> +		SKL_PF_ID_INDEX, &state->scaler_state.scaler_id,
> >> +		state->pipe_src_w, state->pipe_src_h,
> >> +		mode->crtc_hdisplay, mode->crtc_vdisplay);
> >> +}
> >> +
> >>   /**
> >>    * skl_update_scaler_plane - Stages update to scaler state for a given plane.
> >>    *
> >> @@ -6258,6 +6281,15 @@ static int intel_crtc_compute_config(struct intel_crtc *crtc,
> >>   		}
> >>   	}
> >>   
> >> +	if (INTEL_GEN(dev_priv) >= 9) {
> >> +		if (skl_update_scaler_crtc_pf_id_output(pipe_config)) {
> >> +			DRM_ERROR("Unable to set scaler for PF-ID mode\n");
> >> +			return -EINVAL;
> >> +		}
> >> +		intel_pch_panel_fitting(crtc, pipe_config,
> >> +					DRM_MODE_SCALE_FULLSCREEN);
> >> +	}
> >> +
> >>   	if (adjusted_mode->crtc_clock > clock_limit) {
> >>   		DRM_DEBUG_KMS("requested pixel clock (%d kHz) too high (max: %d kHz, double wide: %s)\n",
> >>   			      adjusted_mode->crtc_clock, clock_limit,
> >> @@ -8045,9 +8077,12 @@ static void haswell_set_pipeconf(struct drm_crtc *crtc)
> >>   	if (IS_HASWELL(dev_priv) && intel_crtc->config->dither)
> >>   		val |= (PIPECONF_DITHER_EN | PIPECONF_DITHER_TYPE_SP);
> >>   
> >> -	if (intel_crtc->config->base.adjusted_mode.flags & DRM_MODE_FLAG_INTERLACE)
> >> -		val |= PIPECONF_INTERLACED_ILK;
> >> -	else
> >> +	if (intel_crtc->config->base.adjusted_mode.flags & DRM_MODE_FLAG_INTERLACE) {
> >> +		if (INTEL_GEN(dev_priv) >= 9)
> >> +			val |= PIPECONF_PFIT_PF_INTERLACED_ILK;
> >> +		else
> >> +			val |= PIPECONF_INTERLACED_ILK;
> >> +	} else
> >>   		val |= PIPECONF_PROGRESSIVE;
> >>   
> >>   	I915_WRITE(PIPECONF(cpu_transcoder), val);
> >> diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
> >> index 83dd40905821..d4546f6498b9 100644
> >> --- a/drivers/gpu/drm/i915/intel_drv.h
> >> +++ b/drivers/gpu/drm/i915/intel_drv.h
> >> @@ -483,6 +483,7 @@ struct intel_crtc_scaler_state {
> >>   	 * avilability.
> >>   	 */
> >>   #define SKL_CRTC_INDEX 31
> >> +#define SKL_PF_ID_INDEX 29
> >>   	unsigned scaler_users;
> >>   
> >>   	/* scaler used by crtc for panel fitting purpose */
> >> @@ -1206,6 +1207,15 @@ hdmi_to_dig_port(struct intel_hdmi *intel_hdmi)
> >>   	return container_of(intel_hdmi, struct intel_digital_port, hdmi);
> >>   }
> >>   
> >> +static inline bool
> >> +is_skl_interlace_mode(struct drm_i915_private *dev_priv,
> >> +		      const struct drm_display_mode *mode)
> >> +{
> >> +	if (INTEL_GEN(dev_priv) < 9)
> >> +		return false;
> >> +	return mode->flags & DRM_MODE_FLAG_INTERLACE;
> >> +}
> >> +
> >>   /* intel_fifo_underrun.c */
> >>   bool intel_set_cpu_fifo_underrun_reporting(struct drm_i915_private *dev_priv,
> >>   					   enum pipe pipe, bool enable);
> >> diff --git a/drivers/gpu/drm/i915/intel_panel.c b/drivers/gpu/drm/i915/intel_panel.c
> >> index 4114cb3f14e7..fae7fe7802f8 100644
> >> --- a/drivers/gpu/drm/i915/intel_panel.c
> >> +++ b/drivers/gpu/drm/i915/intel_panel.c
> >> @@ -108,9 +108,14 @@ intel_pch_panel_fitting(struct intel_crtc *intel_crtc,
> >>   	const struct drm_display_mode *adjusted_mode = &pipe_config->base.adjusted_mode;
> >>   	int x = 0, y = 0, width = 0, height = 0;
> >>   
> >> -	/* Native modes don't need fitting */
> >> +	/*
> >> +	 * Native modes don't need fitting
> >> +	 * PF-ID Interlace mode in SKL+ require a pipe scaler
> >> +	 */
> >>   	if (adjusted_mode->crtc_hdisplay == pipe_config->pipe_src_w &&
> >> -	    adjusted_mode->crtc_vdisplay == pipe_config->pipe_src_h)
> >> +	    adjusted_mode->crtc_vdisplay == pipe_config->pipe_src_h &&
> >> +	    !(is_skl_interlace_mode(to_i915(intel_crtc->base.dev),
> >> +				    adjusted_mode)))
> >>   		goto done;
> >>   
> >>   	switch (fitting_mode) {
> >> diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
> >> index aa9d8cef7ce0..dfb21f00fbed 100644
> >> --- a/drivers/gpu/drm/i915/intel_pm.c
> >> +++ b/drivers/gpu/drm/i915/intel_pm.c
> >> @@ -3873,15 +3873,18 @@ static uint_fixed_16_16_t
> >>   skl_pipe_downscale_amount(const struct intel_crtc_state *crtc_state)
> >>   {
> >>   	uint_fixed_16_16_t pipe_downscale = u32_to_fixed_16_16(1);
> >> +	const struct drm_display_mode *mode;
> >>   
> >>   	if (!crtc_state->base.enable)
> >>   		return pipe_downscale;
> >>   
> >> +	mode = &crtc_state->base.adjusted_mode;
> >>   	if (crtc_state->pch_pfit.enabled) {
> >>   		uint32_t src_w, src_h, dst_w, dst_h;
> >>   		uint32_t pfit_size = crtc_state->pch_pfit.size;
> >>   		uint_fixed_16_16_t fp_w_ratio, fp_h_ratio;
> >>   		uint_fixed_16_16_t downscale_h, downscale_w;
> >> +		uint_fixed_16_16_t min_h_downscale;
> >>   
> >>   		src_w = crtc_state->pipe_src_w;
> >>   		src_h = crtc_state->pipe_src_h;
> >> @@ -3891,10 +3894,19 @@ skl_pipe_downscale_amount(const struct intel_crtc_state *crtc_state)
> >>   		if (!dst_w || !dst_h)
> >>   			return pipe_downscale;
> >>   
> >> +		/*
> >> +		 * Interlace mode require 1 scaler so no other scaler can be
> >> +		 * attached to pipe. PF-ID mode is equivalent to 2.0 vertical
> >> +		 * downscale.
> >> +		 */
> >> +		if (mode->flags & DRM_MODE_FLAG_INTERLACE)
> >> +			min_h_downscale = u32_to_fixed_16_16(2);
> >> +		else
> >> +			min_h_downscale = u32_to_fixed_16_16(1);
> >>   		fp_w_ratio = fixed_16_16_div(src_w, dst_w);
> >>   		fp_h_ratio = fixed_16_16_div(src_h, dst_h);
> >>   		downscale_w = max_fixed_16_16(fp_w_ratio, u32_to_fixed_16_16(1));
> >> -		downscale_h = max_fixed_16_16(fp_h_ratio, u32_to_fixed_16_16(1));
> >> +		downscale_h = max_fixed_16_16(fp_h_ratio, min_h_downscale);
> >>   
> >>   		pipe_downscale = mul_fixed16(downscale_w, downscale_h);
> >>   	}
> >> @@ -4418,6 +4430,9 @@ skl_adjusted_plane_pixel_rate(const struct intel_crtc_state *cstate,
> >>   	 * with additional adjustments for plane-specific scaling.
> >>   	 */
> >>   	adjusted_pixel_rate = cstate->pixel_rate;
> >> +	if (cstate->base.adjusted_mode.flags & DRM_MODE_FLAG_INTERLACE)
> >> +		adjusted_pixel_rate *= 2;
> >> +
> >>   	downscale_amount = skl_plane_downscale_amount(cstate, pstate);
> >>   
> >>   	return mul_round_up_u32_fixed16(adjusted_pixel_rate,
> >> -- 
> >> 2.11.0
> >>
> >> _______________________________________________
> >> Intel-gfx mailing list
> >> Intel-gfx@lists.freedesktop.org
> >> https://lists.freedesktop.org/mailman/listinfo/intel-gfx

-- 
Ville Syrjälä
Intel OTC
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