On Mon, 20 Jun 2022, Jouni Högander jouni.hogander@intel.com wrote:
Split luminance min/max calculation using static hdr metadata from drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c:update_connector_ext_caps into drm/drm_edid.c and use it during edid parsing. Calculated range is stored into connector->display_info->luminance_range.
v2: Calculate range during edid parsing
Cc: Roman Li roman.li@amd.com Cc: Rodrigo Siqueira Rodrigo.Siqueira@amd.com Cc: Harry Wentland harry.wentland@amd.com Cc: Lyude Paul lyude@redhat.com Cc: Mika Kahola mika.kahola@intel.com Cc: Jani Nikula jani.nikula@intel.com Cc: Manasi Navare manasi.d.navare@intel.com Signed-off-by: Jouni Högander jouni.hogander@intel.com
drivers/gpu/drm/drm_edid.c | 50 +++++++++++++++++++++++++++++++++++++- 1 file changed, 49 insertions(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c index 2bdaf1e34a9d..3b367100290f 100644 --- a/drivers/gpu/drm/drm_edid.c +++ b/drivers/gpu/drm/drm_edid.c @@ -5014,6 +5014,49 @@ static void fixup_detailed_cea_mode_clock(struct drm_display_mode *mode) mode->clock = clock; }
+static void drm_calculate_luminance_range(struct drm_connector *connector) +{
- struct hdr_static_metadata *hdr_metadata = &connector->hdr_sink_metadata.hdmi_type1;
- struct drm_luminance_range_info *luminance_range =
&connector->display_info.luminance_range;- static const u8 pre_computed_values[] = {
50, 51, 52, 53, 55, 56, 57, 58, 59, 61, 62, 63, 65, 66, 68, 69,71, 72, 74, 75, 77, 79, 81, 82, 84, 86, 88, 90, 92, 94, 96, 98};
Nitpick, newline before };
- u32 max_avg, min_cll, max, min, q, r;
- if (!(hdr_metadata->metadata_type & BIT(HDMI_STATIC_METADATA_TYPE1)))
return;- max_avg = hdr_metadata->max_fall;
- min_cll = hdr_metadata->min_cll;
- /* From the specification (CTA-861-G), for calculating the maximum
Nitpick, newline after /*.
* luminance we need to use:* Luminance = 50*2**(CV/32)* Where CV is a one-byte value.* For calculating this expression we may need float point precision;* to avoid this complexity level, we take advantage that CV is divided* by a constant. From the Euclids division algorithm, we know that CV* can be written as: CV = 32*q + r. Next, we replace CV in the* Luminance expression and get 50*(2**q)*(2**(r/32)), hence we just* need to pre-compute the value of r/32. For pre-computing the values* We just used the following Ruby line:* (0...32).each {|cv| puts (50*2**(cv/32.0)).round}* The results of the above expressions can be verified at* pre_computed_values.*/- q = max_avg >> 5;
- r = max_avg % 32;
- max = (1 << q) * pre_computed_values[r];
- /* min luminance: maxLum * (CV/255)^2 / 100 */
- q = DIV_ROUND_CLOSEST(min_cll, 255);
- min = max * DIV_ROUND_CLOSEST((q * q), 100);
- luminance_range->min_luminance = min;
- luminance_range->max_luminance = max;
I'll just trust this; not going to start verifying.
Acked-by: Jani Nikula jani.nikula@intel.com
+}
static uint8_t eotf_supported(const u8 *edid_ext) { return edid_ext[2] & @@ -5045,8 +5088,12 @@ drm_parse_hdr_metadata_block(struct drm_connector *connector, const u8 *db) connector->hdr_sink_metadata.hdmi_type1.max_cll = db[4]; if (len >= 5) connector->hdr_sink_metadata.hdmi_type1.max_fall = db[5];
- if (len >= 6)
- if (len >= 6) { connector->hdr_sink_metadata.hdmi_type1.min_cll = db[6];
/* Calculate only when all values are available */drm_calculate_luminance_range(connector);- }
}
static void @@ -5951,6 +5998,7 @@ drm_reset_display_info(struct drm_connector *connector)
info->non_desktop = 0; memset(&info->monitor_range, 0, sizeof(info->monitor_range));
memset(&info->luminance_range, 0, sizeof(info->luminance_range));
info->mso_stream_count = 0; info->mso_pixel_overlap = 0;