[PATCH v2 3/6] drm/edid: detect SCDC support in HF-VSDB

[Sharma, Shashank]

Regards

Shashank


On 2/7/2017 4:31 PM, Jose Abreu wrote:
> Hi Shashank,
>
>
>
> On 06-02-2017 13:59, Shashank Sharma wrote:
>> This patch does following:
>> - Adds a new structure (drm_hdmi_info) in drm_display_info.
>>    This structure will be used to save and indicate if sink
>>    supports advanced HDMI 2.0 features
>> - Adds another structure drm_scdc within drm_hdmi_info, to
>>    reflect scdc support and capabilities in connected HDMI 2.0 sink.
>> - Checks the HF-VSDB block for presence of SCDC, and marks it
>>    in scdc structure
>> - If SCDC is present, checks if sink is capable of generating
>>    SCDC read request, and marks it in scdc structure.
>>
>> V2: Addressed review comments
>> Thierry:
>> - Fix typos in commit message and make abbreviation consistent
>>    across the commit message.
>> - Change structure object name from hdmi_info -> hdmi
>> - Fix typos and abbreviations in description of structure drm_hdmi_info
>>    end the description with a full stop.
>> - Create a structure drm_scdc, and keep all information related to SCDC
>>    register set (supported, read request supported) etc in it.
>>
>> Ville:
>> - Change rr -> read_request
>> - Call drm_detect_scrambling function drm_parse_hf_vsdb so that all
>>    of HF-VSDB parsing can be kept in same function, in incremental
>>    patches.
>>
>> Reviewed-by: Thierry Reding <treding at nvidia.com>
>> Signed-off-by: Shashank Sharma <shashank.sharma at intel.com>
>> ---
>>   drivers/gpu/drm/drm_edid.c  | 14 ++++++++++++++
>>   include/drm/drm_connector.h | 33 +++++++++++++++++++++++++++++++++
>>   2 files changed, 47 insertions(+)
>>
>> diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c
>> index 96d3e47..a487b80 100644
>> --- a/drivers/gpu/drm/drm_edid.c
>> +++ b/drivers/gpu/drm/drm_edid.c
>> @@ -3802,6 +3802,18 @@ enum hdmi_quantization_range
>>   }
>>   EXPORT_SYMBOL(drm_default_rgb_quant_range);
>>   
>> +static void drm_parse_hdmi_forum_vsdb(struct drm_connector *connector,
>> +				 const u8 *hf_vsdb)
>> +{
>> +	struct drm_hdmi_info *hdmi = &connector->display_info.hdmi;
>> +
>> +	if (hf_vsdb[6] & 0x80) {
> BIT(7) ?
Yes, SCDC_present bit is bit 7, byte 6 in HF-VSDB. Am I missing something ?
>
>> +		hdmi->scdc.supported = true;
>> +		if (hf_vsdb[6] & 0x40)
> BIT(6) ?
Yes, RR_Capable bit is bit 6, byte 6 in HF-VSDB.
>
>> +			hdmi->scdc.read_request = true;
>> +	}
>> +}
>> +
>>   static void drm_parse_hdmi_deep_color_info(struct drm_connector *connector,
>>   					   const u8 *hdmi)
>>   {
>> @@ -3916,6 +3928,8 @@ static void drm_parse_cea_ext(struct drm_connector *connector,
>>   
>>   		if (cea_db_is_hdmi_vsdb(db))
>>   			drm_parse_hdmi_vsdb_video(connector, db);
>> +		if (cea_db_is_hdmi_forum_vsdb(db))
>> +			drm_parse_hdmi_forum_vsdb(connector, db);
>>   	}
>>   }
>>   
>> diff --git a/include/drm/drm_connector.h b/include/drm/drm_connector.h
>> index e5e1edd..6d5304e 100644
>> --- a/include/drm/drm_connector.h
>> +++ b/include/drm/drm_connector.h
>> @@ -87,6 +87,34 @@ enum subpixel_order {
>>   	SubPixelVerticalRGB,
>>   	SubPixelVerticalBGR,
>>   	SubPixelNone,
>> +
>> +};
>> +
>> +/*
>> + * struct drm_scdc - Information about scdc capabilities of a HDMI 2.0 sink
>> + *
>> + * Provides SCDC register support and capabilities related information on a
>> + * HDMI 2.0 sink. In case of a HDMI 1.4 sink, all parameter must be 0.
>> + */
>> +struct drm_scdc {
>> +	/**
>> +	 * @supported: status control & data channel present.
>> +	 */
>> +	bool supported;
>> +	/**
>> +	 * @read_request: sink is capable of generating scdc read request.
>> +	 */
>> +	bool read_request;
>> +};
>> +
>> +/**
>> + * struct drm_hdmi_info - runtime information about the connected HDMI sink
>> + *
>> + * Describes if a given display supports advanced HDMI 2.0 features.
>> + * This information is available in CEA-861-F extension blocks (like HF-VSDB).
>> + */
>> +struct drm_hdmi_info {
>> +	struct drm_scdc scdc;
>>   };
>>   
>>   /**
>> @@ -188,6 +216,11 @@ struct drm_display_info {
>>   	 * @cea_rev: CEA revision of the HDMI sink.
>>   	 */
>>   	u8 cea_rev;
>> +
>> +	/**
>> +	 * @hdmi: advance features of a HDMI sink.
> Maybe change to the same general description you used above:
> "Runtime information about the connected HDMI sink" ?
Actually the description I used in patch set 1, was similar, but this is 
based on feedbacks from review set 1.
- Shashank
>> +	 */
>> +	struct drm_hdmi_info hdmi;
>>   };
>>   
>>   int drm_display_info_set_bus_formats(struct drm_display_info *info,
> Best regards,
> Jose Miguel Abreu