Re: [PATCH v2] drm/edid: Fill PAR in AVI infoframe based on CEA mode list

[Vandana Kannan <vandana.kannan@intel.com>]

On Apr-01-2014 5:04 PM, Ville Syrjälä wrote:
> On Tue, Apr 01, 2014 at 04:26:59PM +0530, Vandana Kannan wrote:
>> Populate PAR in infoframe structure. If there is a user setting for PAR, then
>> that value is set. Else, value is taken from CEA mode list if VIC is found.
>> Else, PAR is calculated from resolution. If none of these conditions are
>> satisfied, PAR is NONE as per initialization.
>>
>> v2: Removed the part which sets PAR according to user input, based on
>> Daniel's review comments.
>>
>> A separate patch will be submitted to create a property that would enable a
>> user space app to set aspect ratio for AVI infoframe.
>>
>> Signed-off-by: Vandana Kannan <vandana.kannan@intel.com>
>> Cc: Jesse Barnes <jesse.barnes@intel.com>
>> Cc: Vijay Purushothaman <vijay.a.purushothaman@intel.com>
>> Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
>> Cc: intel-gfx@lists.freedesktop.org
>> Reviewed-by: Jesse Barnes <jbarnes@virtuousgeek.org>
>> ---
>>  drivers/gpu/drm/drm_edid.c | 29 +++++++++++++++++++++++++++++
>>  include/drm/drm_crtc.h     |  1 +
>>  2 files changed, 30 insertions(+)
>>
>> diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c
>> index d4e3f9d..fee24d3 100644
>> --- a/drivers/gpu/drm/drm_edid.c
>> +++ b/drivers/gpu/drm/drm_edid.c
>> @@ -2452,6 +2452,21 @@ u8 drm_match_cea_mode(const struct drm_display_mode *to_match)
>>  }
>>  EXPORT_SYMBOL(drm_match_cea_mode);
>>  
>> +/**
>> + * drm_get_cea_aspect_ratio - get the picture aspect ratio corresponding to
>> + * the input VIC from the CEA mode list
>> + *
>> + * Returns picture aspect ratio
>> + */
>> +enum hdmi_picture_aspect drm_get_cea_aspect_ratio(const u8 video_code)
>> +{
>> +	/* return picture aspect ratio for video_code - 1 to access the
>> +	 * right array element
>> +	*/
>> +	return edid_cea_modes[video_code-1].picture_aspect_ratio;
>> +}
>> +EXPORT_SYMBOL(drm_get_cea_aspect_ratio);
>> +
>>  /*
>>   * Calculate the alternate clock for HDMI modes (those from the HDMI vendor
>>   * specific block).
>> @@ -3613,6 +3628,20 @@ drm_hdmi_avi_infoframe_from_display_mode(struct hdmi_avi_infoframe *frame,
>>  	frame->video_code = drm_match_cea_mode(mode);
>>  
>>  	frame->picture_aspect = HDMI_PICTURE_ASPECT_NONE;
>> +
>> +	/* Populate picture aspect ratio from CEA mode list */
>> +	if (frame->video_code > 0)
>> +		frame->picture_aspect = drm_get_cea_aspect_ratio(
>> +						frame->video_code);
>> +	else {
>> +		if (!(mode->vdisplay % 3) &&
>> +			(((mode->vdisplay * 4) / 3) == mode->hdisplay))
>> +			frame->picture_aspect = HDMI_PICTURE_ASPECT_4_3;
>> +		else if (!(mode->vdisplay % 9) &&
>> +			(((mode->vdisplay * 16) / 9) == mode->hdisplay))
>> +			frame->picture_aspect = HDMI_PICTURE_ASPECT_16_9;
>> +	}
> 
> I'm not sure if providing the PAR for non-CEA modes like this makes
> any real difference. But I guess it can't hurt since you only provide
> it for exact matches.
> 
> But the matches are maybe even a bit too exact. For instance 1366x768
> will not match the 16:9 case. So maybe it should be calculated in a bit
> more relaxed way.
> 
> Or just dropped totally. I'm not sure.
> 
Maybe we can drop it for now (for this patch) and come up with another
patch containing calculations which are more relaxed than the above.
What do you think?
>> +
>>  	frame->active_aspect = HDMI_ACTIVE_ASPECT_PICTURE;
>>  	frame->scan_mode = HDMI_SCAN_MODE_UNDERSCAN;
>>  
>> diff --git a/include/drm/drm_crtc.h b/include/drm/drm_crtc.h
>> index 27f828c..50dc55a 100644
>> --- a/include/drm/drm_crtc.h
>> +++ b/include/drm/drm_crtc.h
>> @@ -983,6 +983,7 @@ extern int drm_mode_gamma_get_ioctl(struct drm_device *dev,
>>  extern int drm_mode_gamma_set_ioctl(struct drm_device *dev,
>>  				    void *data, struct drm_file *file_priv);
>>  extern u8 drm_match_cea_mode(const struct drm_display_mode *to_match);
>> +extern enum hdmi_picture_aspect drm_get_cea_aspect_ratio(const u8 video_code);
>>  extern bool drm_detect_hdmi_monitor(struct edid *edid);
>>  extern bool drm_detect_monitor_audio(struct edid *edid);
>>  extern bool drm_rgb_quant_range_selectable(struct edid *edid);
>> -- 
>> 1.9.1
>