[Intel-gfx] [PATCH v6 5/6] drm/i915: enable scrambling

Sharma, Shashank shashank.sharma at intel.com
Fri Mar 3 16:03:22 UTC 2017


Regards

Shashank


On 3/3/2017 6:31 PM, Ander Conselvan De Oliveira wrote:
> On Fri, 2017-03-03 at 17:33 +0530, Sharma, Shashank wrote:
>> Thanks for the review Ander. My comments inline.
>>
>> Shashank
>>
>> On 3/3/2017 3:22 PM, Ander Conselvan De Oliveira wrote:
>>> On Fri, 2017-03-03 at 11:59 +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.
>>>>
>>>> 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     | 33 ++++++++++++++++
>>>>    drivers/gpu/drm/i915/intel_display.c |  5 +++
>>>>    drivers/gpu/drm/i915/intel_drv.h     | 14 +++++++
>>>>    drivers/gpu/drm/i915/intel_hdmi.c    | 74 ++++++++++++++++++++++++++++++++++++
>>>>    5 files changed, 133 insertions(+)
>>>>
>>>> diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
>>>> index 4906ce4d..f7891ac 100644
>>>> --- a/drivers/gpu/drm/i915/i915_reg.h
>>>> +++ b/drivers/gpu/drm/i915/i915_reg.h
>>>> @@ -7824,7 +7824,14 @@ 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)
>>> Last line is misaligned.
>> Ok.
>>>>    
>>>>    /* 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 a7c08d7..d0c6927 100644
>>>> --- a/drivers/gpu/drm/i915/intel_ddi.c
>>>> +++ b/drivers/gpu/drm/i915/intel_ddi.c
>>>> @@ -1311,6 +1311,11 @@ void intel_ddi_enable_transcoder_func(struct drm_crtc *crtc)
>>>>    			temp |= TRANS_DDI_MODE_SELECT_HDMI;
>>>>    		else
>>>>    			temp |= TRANS_DDI_MODE_SELECT_DVI;
>>>> +
>>>> +		if (IS_GEMINILAKE(dev_priv))
>>>> +			temp = intel_hdmi_handle_source_scrambling(
>>>> +				intel_encoder,
>>>> +				intel_crtc->config, temp);
>>> This whole hunk could just be:
>>>
>>> +	if (config->hdmi_scrambling)
>>> +		hdmi_config |= TRANS_DDI_HDMI_SCRAMBLING_MASK;
>>> +
>>> +	if (config->hdmi_high_tmds_clock_ratio)
>>> +		hdmi_config |= TRANS_DDI_HIGH_TMDS_CHAR_RATE;
>>>
>>> No need to check for GLK here, since the compute config code already did.
>> As I was emphasizing in the previous review comments, having two
>> separate functions, one to set source_scrambling and
>> other to set sink_scrambling makes it easy to follow up, due to design
>> symmetry, and in that case you need not to refer
>> to bspec to find out which all registers be dealing with scrambling ,
>> just check for scrambling control functions. So I was insisting
>> on keeping them.
> But that design creates an asymmetry when it comes to checking all bits that are
> enabled in TRANS_DDI_FUNC_CTL() that involves function-hopping. Maybe it is just
> a matter of different taste. But for the more practical problem of finding what
> bits are involved in enabling scrambling, I think
>
>      git grep hdmi_scrambling
>
> will do a good enough job.
Will do this.
>> But anyways, both you and Ville are insisting on keeping it inline, so
>> lets keep it that way.
>>>>    	} else if (type == INTEL_OUTPUT_ANALOG) {
>>>>    		temp |= TRANS_DDI_MODE_SELECT_FDI;
>>>>    		temp |= (intel_crtc->config->fdi_lanes - 1) << 1;
>>>> @@ -1885,6 +1890,21 @@ static void intel_enable_ddi(struct intel_encoder *intel_encoder,
>>>>    		struct intel_digital_port *intel_dig_port =
>>>>    			enc_to_dig_port(encoder);
>>>>    
>>>> +		if (IS_GEMINILAKE(dev_priv)) {
>>>> +			struct intel_crtc *crtc = to_intel_crtc(encoder->crtc);
>>>> +			/*
>>>> +			 * GLK sports a native HDMI 2.0 controller. If required
>>>> +			 * clock rate is > 340 Mhz && scrambling is supported
>>>> +			 * by sink, enable scrambling before enabling the
>>>> +			 * HDMI 2.0 port. The sink can choose to disable the
>>>> +			 * scrambling if it doesn't detect a scrambled within
>>>> +			 * 100 ms.
>>>> +			 */
>>>> +			intel_hdmi_handle_sink_scrambling(intel_encoder,
>>>> +						conn_state->connector,
>>>> +						crtc->config, true);
>>> This function receives a pipe_config pointer as argument. Use that instead of
>>> crtc->config.
>> Ok.
>>>> +		}
>>>> +
>>>>    		/* In HDMI/DVI mode, the port width, and swing/emphasis values
>>>>    		 * are ignored so nothing special needs to be done besides
>>>>    		 * enabling the port.
>>>> @@ -1917,6 +1937,14 @@ 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) {
>>>> +		struct intel_crtc *intel_crtc = to_intel_crtc(encoder->crtc);
>>>> +
>>>> +		intel_hdmi_handle_sink_scrambling(intel_encoder,
>>>> +					old_conn_state->connector,
>>>> +					intel_crtc->config, false);
>>>> +	}
>>>> +
>>>>    	if (type == INTEL_OUTPUT_EDP) {
>>>>    		struct intel_dp *intel_dp = enc_to_intel_dp(encoder);
>>>>    
>>>> @@ -2044,6 +2072,11 @@ 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)
> I missed this the first time, but we say hdmi_scrambling is enabled if any of
> those bits in the mask is set. Is that really what we want? Or should this check
> specifically for the TRANS_DDI_HDMI_SCRAMBLING bit or all the bits set?
Initially I thought of any of those bits in the mask, but now I am 
thinking we are always setting all of those bits
togother, and as per the bspec, all of it is required, so I will add it 
like this:
(temp & TRANS_DDI_HDMI_SCRAMBLING_MASK == TRANS_DDI_HDMI_SCRAMBLING_MASK)

Shashank
>>>> +			pipe_config->hdmi_scrambling = true;
>>>> +		if (temp & TRANS_DDI_HIGH_TMDS_CHAR_RATE)
>>>> +			pipe_config->hdmi_high_tmds_clock_ratio = true;
>>> Hmm, we might need a IS_GLK here, since these bits only exist in that platform.
>>> I believe they should read zero though, since they are listed are reserved.
>>> Dunno.
>> Hmm, I dont think there would be a way to set the reserved bits though,
>> so we can keep it. In this way the
>> only place we are checking and setting the platform is compute_config.
> Yeah, with the change to check the state for non-GLK too, we get a WARN if this
> fails, so seems ok.
>
>>>>    		/* 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 99e8d9c..c017ed3 100644
>>>> --- a/drivers/gpu/drm/i915/intel_display.c
>>>> +++ b/drivers/gpu/drm/i915/intel_display.c
>>>> @@ -11662,6 +11662,11 @@ 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);
>>>> +	if (IS_GEMINILAKE(dev_priv)) {
>>> No need to check for GLK here. The configuration should never be set for other
>>> platforms. If it is set, that's a bug and we want verify_crtc_state() to tells
>>> us about it.
>> Agree, will remove this.
>>>> +		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 e6fbbee..baefbaa 100644
>>>> --- a/drivers/gpu/drm/i915/intel_drv.h
>>>> +++ b/drivers/gpu/drm/i915/intel_drv.h
>>>> @@ -695,6 +695,12 @@ struct intel_crtc_state {
>>>>    
>>>>    	/* Gamma mode programmed on the pipe */
>>>>    	uint32_t gamma_mode;
>>>> +
>>>> +	/* HDMI scrambling status (sink) */
>>>> +	bool hdmi_scrambling;
>>>> +
>>>> +	/* HDMI High TMDS char rate ratio (sink) */
>>>> +	bool hdmi_high_tmds_clock_ratio;
>>>>    };
>>>>    
>>>>    struct vlv_wm_state {
>>>> @@ -1626,6 +1632,14 @@ 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);
>>>> +uint32_t
>>>> +intel_hdmi_handle_source_scrambling(struct intel_encoder *intel_encoder,
>>>> +					struct intel_crtc_state *config,
>>>> +					uint32_t hdmi_config);
>>>> +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..0a1ae03 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 +1806,68 @@ static void intel_hdmi_destroy(struct drm_connector *connector)
>>>>    	intel_hdmi->aspect_ratio = HDMI_PICTURE_ASPECT_NONE;
>>>>    }
>>>>    
>>>> +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;
>>>> +
>>>> +	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");
>>>> +}
>>>> +
>>>> +uint32_t
>>>> +intel_hdmi_handle_source_scrambling(struct intel_encoder *intel_encoder,
>>>> +			struct intel_crtc_state *config, uint32_t hdmi_config)
>>>> +{
>>>> +	struct intel_hdmi *intel_hdmi = enc_to_intel_hdmi(&intel_encoder->base);
>>>> +	struct drm_connector *connector = &intel_hdmi->attached_connector->base;
>>>> +
>>>> +	DRM_DEBUG_KMS("Setting scrambling for enc:%s connector:%s\n",
>>>> +			intel_encoder->base.name, connector->name);
>>> Instead of debugging here, print the hdmi scrambling values in
>>> intel_dump_pipe_config().
>> I am also interested in which encoder and connector are we setting the
>> values for, is it that bad :) ?
> The debug for the modeset should tell you that, but IMO it would be ok to leave
> this extra debug message if the function would still exist.
>
> Ander
>
>>>> +	hdmi_config &= ~(TRANS_DDI_HDMI_SCRAMBLING_MASK |
>>>> +		TRANS_DDI_HIGH_TMDS_CHAR_RATE);
>>> This is unnecessary. The hunk below belongs in
>>> intel_ddi_enable_transcoder_func() and that function does not do read-modify-
>>> write. Any bit that is not explicitly set is zero. I think things are just
>>> simpler if this function doesn't exist.
>> Yeah, will do that.
>>> Ander
>>>
>>>> +	if (config->hdmi_scrambling)
>>>> +		hdmi_config |= TRANS_DDI_HDMI_SCRAMBLING_MASK;
>>>> +
>>>> +	if (config->hdmi_high_tmds_clock_ratio)
>>>> +		hdmi_config |= TRANS_DDI_HIGH_TMDS_CHAR_RATE;
>>>> +
>>>> +	return hdmi_config;
>>>> +}
>>>> +
>>>>    static u8 intel_hdmi_ddc_pin(struct drm_i915_private *dev_priv,
>>>>    			     enum port port)
>>>>    {
>>



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