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

Sharma, Shashank
2017-02-07T16:13:15Z

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@nvidia.com>
>> Signed-off-by: Shashank Sharma <shashank.sharma@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