[Intel-gfx] [PATCH v8 5/6] drm/i915: enable scrambling

Ville Syrjälä ville.syrjala at linux.intel.com
Wed Mar 8 17:44:45 UTC 2017


On Wed, Mar 08, 2017 at 07:26:45PM +0200, Sharma, Shashank wrote:
> Regards
> 
> Shashank
> 
> 
> On 3/8/2017 7:17 PM, Ville Syrjälä wrote:
> > On Wed, Mar 08, 2017 at 07:07:48PM +0530, Shashank Sharma wrote:
> >>   Geminilake platform sports a native HDMI 2.0 controller, and is
> >>   capable of driving pixel-clocks upto 594Mhz. HDMI 2.0 spec
> >>   mendates scrambling for these higher clocks, for reduced RF footprint.
> >>
> >>   This patch checks if the monitor supports scrambling, and if required,
> >>   enables it during the modeset.
> >>
> >>   V2: Addressed review comments from Ville:
> >>   - Do not track scrambling status in DRM layer, track somewhere in
> >>     driver like in intel_crtc_state.
> >>   - Don't talk to monitor at such a low layer, set monitor scrambling
> >>     in intel_enable_ddi() before enabling the port.
> >>
> >>   V3: Addressed review comments from Jani
> >>   - In comments, function names, use "sink" instead of "monitor",
> >>     so that the implementation could be close to the language of
> >>     HDMI spec.
> >>
> >> V4: Addressed review comment from Maarten
> >>   - scrambling -> hdmi_scrambling
> >>   - high_tmds_clock_ratio -> hdmi_high_tmds_clock_ratio
> >>
> >> V5: Addressed review comments from Ville and Ander
> >>   - Do not modifiy the crtc_state after compute_config. Move all
> >>     scrambling and tmds_clock_ratio calcutations to compute_config.
> >>   - While setting scrambling for source/sink, do not check the
> >>     conditions again, just go by the crtc_state flags. This will
> >>     simplyfy the condition checks.
> >>
> >> V6: Addressed review comments from Ville
> >>   - Do not add IS_GLK check in disable/enable function, instead add it
> >>     in compute_config, while setting state flags.
> >>   - Remove unnecessary paranthesis.
> >>   - Simplyfy handle_sink_scrambling function as suggested.
> >>   - Add readout code for scrambling status in get_ddi_config and add a
> >>     check for the same in pipe_config_compare.
> >>
> >> V7: Addressed review comments from Ander/Ville
> >>   - No separate function for source scrambling, make it inline
> >>   - Align the last line of the macro TRANS_DDI_HDMI_SCRAMBLING_MASK
> >>   - Do not add platform check while setting source scrambling
> >>   - Use pipe_config instead of crtc->config to set sink scrambling
> >>   - To readout scrambling status, Compare with SCRAMBLING_MASK
> >>     not any of its bits
> >>   - Remove platform check in intel_pipe_config_compare while checking
> >>     scrambling status
> >>
> >> V8: Fixed mege conflict, Addressed review comments from Ander
> >>   - Remove the desciption/comment about scrambling fom the caller, move
> >>     it to the function
> >>   - Move the IS_GLK check into scrambling function
> >>   - Fix alignment
> >>
> >> Signed-off-by: Shashank Sharma <shashank.sharma at intel.com>
> >> ---
> >>   drivers/gpu/drm/i915/i915_reg.h      |  7 ++++
> >>   drivers/gpu/drm/i915/intel_ddi.c     | 19 +++++++++++
> >>   drivers/gpu/drm/i915/intel_display.c |  3 ++
> >>   drivers/gpu/drm/i915/intel_drv.h     | 10 ++++++
> >>   drivers/gpu/drm/i915/intel_hdmi.c    | 62 ++++++++++++++++++++++++++++++++++++
> >>   5 files changed, 101 insertions(+)
> >>
> >> diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
> >> index cc843f9..2d50fdc 100644
> >> --- a/drivers/gpu/drm/i915/i915_reg.h
> >> +++ b/drivers/gpu/drm/i915/i915_reg.h
> >> @@ -7830,7 +7830,14 @@ enum {
> >>   #define  TRANS_DDI_EDP_INPUT_B_ONOFF	(5<<12)
> >>   #define  TRANS_DDI_EDP_INPUT_C_ONOFF	(6<<12)
> >>   #define  TRANS_DDI_DP_VC_PAYLOAD_ALLOC	(1<<8)
> >> +#define  TRANS_DDI_HDMI_SCRAMBLER_CTS_ENABLE (1<<7)
> >> +#define  TRANS_DDI_HDMI_SCRAMBLER_RESET_FREQ (1<<6)
> >>   #define  TRANS_DDI_BFI_ENABLE		(1<<4)
> >> +#define  TRANS_DDI_HIGH_TMDS_CHAR_RATE	(1<<4)
> >> +#define  TRANS_DDI_HDMI_SCRAMBLING	(1<<0)
> >> +#define  TRANS_DDI_HDMI_SCRAMBLING_MASK (TRANS_DDI_HDMI_SCRAMBLER_CTS_ENABLE \
> >> +					| TRANS_DDI_HDMI_SCRAMBLER_RESET_FREQ \
> >> +					| TRANS_DDI_HDMI_SCRAMBLING)
> >>   
> >>   /* DisplayPort Transport Control */
> >>   #define _DP_TP_CTL_A			0x64040
> >> diff --git a/drivers/gpu/drm/i915/intel_ddi.c b/drivers/gpu/drm/i915/intel_ddi.c
> >> index 0467676..b3e4c4a 100644
> >> --- a/drivers/gpu/drm/i915/intel_ddi.c
> >> +++ b/drivers/gpu/drm/i915/intel_ddi.c
> >> @@ -1309,6 +1309,11 @@ void intel_ddi_enable_transcoder_func(const struct intel_crtc_state *crtc_state)
> >>   			temp |= TRANS_DDI_MODE_SELECT_HDMI;
> >>   		else
> >>   			temp |= TRANS_DDI_MODE_SELECT_DVI;
> >> +
> >> +		if (crtc_state->hdmi_scrambling)
> >> +			temp |= TRANS_DDI_HDMI_SCRAMBLING_MASK;
> >> +		if (crtc_state->hdmi_high_tmds_clock_ratio)
> >> +			temp |= TRANS_DDI_HIGH_TMDS_CHAR_RATE;
> >>   	} else if (type == INTEL_OUTPUT_ANALOG) {
> >>   		temp |= TRANS_DDI_MODE_SELECT_FDI;
> >>   		temp |= (crtc_state->fdi_lanes - 1) << 1;
> >> @@ -1882,6 +1887,9 @@ static void intel_enable_ddi(struct intel_encoder *intel_encoder,
> >>   		struct intel_digital_port *intel_dig_port =
> >>   			enc_to_dig_port(encoder);
> >>   
> >> +		intel_hdmi_handle_sink_scrambling(intel_encoder,
> >> +			conn_state->connector, pipe_config, true);
> >> +
> >>   		/* In HDMI/DVI mode, the port width, and swing/emphasis values
> >>   		 * are ignored so nothing special needs to be done besides
> >>   		 * enabling the port.
> >> @@ -1914,6 +1922,11 @@ static void intel_disable_ddi(struct intel_encoder *intel_encoder,
> >>   	if (old_crtc_state->has_audio)
> >>   		intel_audio_codec_disable(intel_encoder);
> >>   
> >> +	if (type == INTEL_OUTPUT_HDMI) {
> >> +		intel_hdmi_handle_sink_scrambling(intel_encoder,
> >> +			old_conn_state->connector, old_crtc_state, false);
> >> +	}
> >> +
> >>   	if (type == INTEL_OUTPUT_EDP) {
> >>   		struct intel_dp *intel_dp = enc_to_intel_dp(encoder);
> >>   
> >> @@ -2040,6 +2053,12 @@ void intel_ddi_get_config(struct intel_encoder *encoder,
> >>   
> >>   		if (intel_hdmi->infoframe_enabled(&encoder->base, pipe_config))
> >>   			pipe_config->has_infoframe = true;
> >> +
> >> +		if ((temp & TRANS_DDI_HDMI_SCRAMBLING_MASK) ==
> >> +				TRANS_DDI_HDMI_SCRAMBLING_MASK)
> >> +			pipe_config->hdmi_scrambling = true;
> >> +		if (temp & TRANS_DDI_HIGH_TMDS_CHAR_RATE)
> >> +			pipe_config->hdmi_high_tmds_clock_ratio = true;
> >>   		/* fall through */
> >>   	case TRANS_DDI_MODE_SELECT_DVI:
> >>   		pipe_config->lane_count = 4;
> >> diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
> >> index e77ca7d..fb5e670 100644
> >> --- a/drivers/gpu/drm/i915/intel_display.c
> >> +++ b/drivers/gpu/drm/i915/intel_display.c
> >> @@ -11701,6 +11701,9 @@ static void __printf(3, 4)
> >>   	if ((INTEL_GEN(dev_priv) < 8 && !IS_HASWELL(dev_priv)) ||
> >>   	    IS_VALLEYVIEW(dev_priv) || IS_CHERRYVIEW(dev_priv))
> >>   		PIPE_CONF_CHECK_I(limited_color_range);
> >> +
> >> +	PIPE_CONF_CHECK_I(hdmi_scrambling);
> >> +	PIPE_CONF_CHECK_I(hdmi_high_tmds_clock_ratio);
> >>   	PIPE_CONF_CHECK_I(has_infoframe);
> >>   
> >>   	PIPE_CONF_CHECK_I(has_audio);
> >> diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
> >> index 3af20c1..50d680c 100644
> >> --- a/drivers/gpu/drm/i915/intel_drv.h
> >> +++ b/drivers/gpu/drm/i915/intel_drv.h
> >> @@ -729,6 +729,12 @@ struct intel_crtc_state {
> >>   
> >>   	/* bitmask of visible planes (enum plane_id) */
> >>   	u8 active_planes;
> >> +
> >> +	/* HDMI scrambling status */
> >> +	bool hdmi_scrambling;
> >> +
> >> +	/* HDMI High TMDS char rate ratio */
> >> +	bool hdmi_high_tmds_clock_ratio;
> >>   };
> >>   
> >>   struct intel_crtc {
> >> @@ -1623,6 +1629,10 @@ void intel_hdmi_init_connector(struct intel_digital_port *intel_dig_port,
> >>   bool intel_hdmi_compute_config(struct intel_encoder *encoder,
> >>   			       struct intel_crtc_state *pipe_config,
> >>   			       struct drm_connector_state *conn_state);
> >> +void intel_hdmi_handle_sink_scrambling(struct intel_encoder *intel_encoder,
> >> +					struct drm_connector *connector,
> >> +					struct intel_crtc_state *config,
> >> +					bool enable);
> >>   void intel_dp_dual_mode_set_tmds_output(struct intel_hdmi *hdmi, bool enable);
> >>   
> >>   
> >> diff --git a/drivers/gpu/drm/i915/intel_hdmi.c b/drivers/gpu/drm/i915/intel_hdmi.c
> >> index c2184f7..4585aa8 100644
> >> --- a/drivers/gpu/drm/i915/intel_hdmi.c
> >> +++ b/drivers/gpu/drm/i915/intel_hdmi.c
> >> @@ -34,6 +34,7 @@
> >>   #include <drm/drm_atomic_helper.h>
> >>   #include <drm/drm_crtc.h>
> >>   #include <drm/drm_edid.h>
> >> +#include <drm/drm_scdc_helper.h>
> >>   #include "intel_drv.h"
> >>   #include <drm/i915_drm.h>
> >>   #include <drm/intel_lpe_audio.h>
> >> @@ -1316,6 +1317,7 @@ bool intel_hdmi_compute_config(struct intel_encoder *encoder,
> >>   	struct intel_hdmi *intel_hdmi = enc_to_intel_hdmi(&encoder->base);
> >>   	struct drm_i915_private *dev_priv = to_i915(encoder->base.dev);
> >>   	struct drm_display_mode *adjusted_mode = &pipe_config->base.adjusted_mode;
> >> +	struct drm_scdc *scdc = &conn_state->connector->display_info.hdmi.scdc;
> >>   	int clock_8bpc = pipe_config->base.adjusted_mode.crtc_clock;
> >>   	int clock_12bpc = clock_8bpc * 3 / 2;
> >>   	int desired_bpp;
> >> @@ -1385,6 +1387,16 @@ bool intel_hdmi_compute_config(struct intel_encoder *encoder,
> >>   
> >>   	pipe_config->lane_count = 4;
> >>   
> >> +	if (scdc->scrambling.supported && IS_GEMINILAKE(dev_priv)) {
> >> +		if (scdc->scrambling.low_rates)
> >> +			pipe_config->hdmi_scrambling = true;
> >> +
> >> +		if (pipe_config->port_clock > 340000) {
> >> +			pipe_config->hdmi_scrambling = true;
> >> +			pipe_config->hdmi_high_tmds_clock_ratio = true;
> >> +		}
> >> +	}
> >> +
> >>   	return true;
> >>   }
> >>   
> >> @@ -1794,6 +1806,56 @@ static void intel_hdmi_destroy(struct drm_connector *connector)
> >>   	intel_hdmi->aspect_ratio = HDMI_PICTURE_ASPECT_NONE;
> >>   }
> >>   
> >> +/*
> >> + * This function handles scrambling on HDMI 2.0 capable sinks.
> >> + * If required clock rate is > 340 Mhz && scrambling is supported by sink
> >> + * it enables scrambling. This should be called before enabling the HDMI
> >> + * 2.0 port, as the sink can choose to disable the scrambling if it doesn't
> >> + * detect a scrambled clock within 100 ms.
> >> + */
> >> +void intel_hdmi_handle_sink_scrambling(struct intel_encoder *intel_encoder,
> >> +				       struct drm_connector *connector,
> >> +				       struct intel_crtc_state *config,
> >> +				       bool enable)
> >> +{
> >> +	struct intel_hdmi *intel_hdmi = enc_to_intel_hdmi(&intel_encoder->base);
> >> +	struct drm_i915_private *dev_priv = connector->dev->dev_private;
> >> +	struct drm_scrambling *scrambling =
> >> +				&connector->display_info.hdmi.scdc.scrambling;
> >> +	struct i2c_adapter *adptr = intel_gmbus_get_adapter(dev_priv,
> >> +							  intel_hdmi->ddc_bus);
> >> +	bool ret;
> >> +
> >> +	if (!scrambling->supported)
> >> +		return;
> >> +
> >> +	if (!IS_GEMINILAKE(dev_priv))
> >> +		return;
> > I'd still like to see this getting done uncoditionally. That way we
> > might get a bit of extra testing for the SCDC helper no matter what
> > platform the user happens to own.
> Sure, seems a good idea. I just added this hear to address the review 
> comment from Ander.
> Also, I can move this IS_GLK condition to compute_config, and once we 
> check this in compute_config
> we might never have check it again.

I thought you already had the check in there? Hmm. Looks that way to me.

> > I presume the spec says the sink will reset these to some default value
> > on HPD or something like that? But I'm not sure trusting them to get
> > this right is a good idea because reality often doesn't match the
> > specs. So the safer option IMO would be always tell the sink exactly
> > what we want.
> Yep, You are correct about the spec too, that it says if there is no 
> scrambled clock post hpd_out for
> 100ms, the sink should disable scrambling. But connected modeset 
> scenarios need our attention, where
> for example we are switching mode from, 4k at 60 (scrambling reqd) -> 
> 1080 at 60 (scrambling not reqd).
> For such cases too, we have to tell sink to disable scrambling.
> >
> >> +
> >> +	DRM_DEBUG_KMS("Setting sink scrambling for enc:%s connector:%s\n",
> >> +			intel_encoder->base.name, connector->name);
> >> +
> >> +	if (config->hdmi_high_tmds_clock_ratio) {
> >> +		/* Set TMDS bit clock ratio to 1/40 or 1/10 */
> >> +		ret = drm_scdc_set_high_tmds_clock_ratio(adptr, enable);
> >> +		if (!ret) {
> >> +			DRM_ERROR("Set TMDS ratio failed\n");
> >> +			return;
> >> +		}
> >> +	}
> >> +
> >> +	if (config->hdmi_scrambling) {
> >> +		/* Enable/disable sink scrambling */
> >> +		ret = drm_scdc_set_scrambling(adptr, enable);
> >> +		if (!ret) {
> >> +			DRM_ERROR("Set sink scrambling failed\n");
> >> +			return;
> >> +		}
> >> +	}
> >> +
> >> +	DRM_DEBUG_KMS("sink scrambling handled\n");
> >> +}
> >> +
> >>   static u8 intel_hdmi_ddc_pin(struct drm_i915_private *dev_priv,
> >>   			     enum port port)
> >>   {
> >> -- 
> >> 1.9.1

-- 
Ville Syrjälä
Intel OTC


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