Re: [PATCH v4 2/2] drm/dp: Add function to parse EDID descriptors for adaptive sync limits

Kazlauskas, Nicholas
2020-03-06T15:02:43Z

On 2020-03-05 8:42 p.m., Manasi Navare wrote:
> Adaptive Sync is a VESA feature so add a DRM core helper to parse
> the EDID's detailed descritors to obtain the adaptive sync monitor range.
> Store this info as part fo drm_display_info so it can be used
> across all drivers.
> This part of the code is stripped out of amdgpu's function
> amdgpu_dm_update_freesync_caps() to make it generic and be used
> across all DRM drivers
>
> v4:
> * Use is_display_descriptor() (Ville)
> * Name the monitor range flags (Ville)
> v3:
> * Remove the edid parsing restriction for just DP (Nicholas)
> * Use drm_for_each_detailed_block (Ville)
> * Make the drm_get_adaptive_sync_range function static (Harry, Jani)
> v2:
> * Change vmin and vmax to use u8 (Ville)
> * Dont store pixel clock since that is just a max dotclock
> and not related to VRR mode (Manasi)
>
> Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
> Cc: Harry Wentland <harry.wentland@amd.com>
> Cc: Clinton A Taylor <clinton.a.taylor@intel.com>
> Cc: Kazlauskas Nicholas <Nicholas.Kazlauskas@amd.com>
> Signed-off-by: Manasi Navare <manasi.d.navare@intel.com>

Looks good to me now. I'm fine with whether we want to rename the flags
or not, I don't have much of a preference either way.

Series is:

Reviewed-by: Nicholas Kazlauskas <nicholas.kazlauskas@amd.com>

Regards,
Nicholas Kazlauskas

> ---
> drivers/gpu/drm/drm_edid.c | 44 +++++++++++++++++++++++++++++++++++++
> include/drm/drm_connector.h | 22 +++++++++++++++++++
> 2 files changed, 66 insertions(+)
>
> diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c
> index ad41764a4ebe..61ed544d9535 100644
> --- a/drivers/gpu/drm/drm_edid.c
> +++ b/drivers/gpu/drm/drm_edid.c
> @@ -4938,6 +4938,47 @@ static void drm_parse_cea_ext(struct drm_connector *connector,
> }
> }
>
> +static
> +void get_adaptive_sync_range(struct detailed_timing *timing,
> + void *info_adaptive_sync)
> +{
> + struct drm_adaptive_sync_info *adaptive_sync = info_adaptive_sync;
> + const struct detailed_non_pixel *data = &timing->data.other_data;
> + const struct detailed_data_monitor_range *range = &data->data.range;
> +
> + if (!is_display_descriptor((const u8 *)timing, EDID_DETAIL_MONITOR_RANGE))
> + return;
> +
> + /*
> + * Check for flag range limits only. If flag == 1 then
> + * no additional timing information provided.
> + * Default GTF, GTF Secondary curve and CVT are not
> + * supported
> + */
> + if (range->flags != EDID_RANGE_LIMITS_ONLY_FLAG)
> + return;
> +
> + adaptive_sync->min_vfreq = range->min_vfreq;
> + adaptive_sync->max_vfreq = range->max_vfreq;
> +}
> +
> +static
> +void drm_get_adaptive_sync_range(struct drm_connector *connector,
> + const struct edid *edid)
> +{
> + struct drm_display_info *info = &connector->display_info;
> +
> + if (!version_greater(edid, 1, 1))
> + return;
> +
> + drm_for_each_detailed_block((u8 *)edid, get_adaptive_sync_range,
> + &info->adaptive_sync);
> +
> + DRM_DEBUG_KMS("Adaptive Sync refresh rate range is %d Hz - %d Hz\n",
> + info->adaptive_sync.min_vfreq,
> + info->adaptive_sync.max_vfreq);
> +}
> +
> /* A connector has no EDID information, so we've got no EDID to compute quirks from. Reset
> * all of the values which would have been set from EDID
> */
> @@ -4960,6 +5001,7 @@ drm_reset_display_info(struct drm_connector *connector)
> memset(&info->hdmi, 0, sizeof(info->hdmi));
>
> info->non_desktop = 0;
> + memset(&info->adaptive_sync, 0, sizeof(info->adaptive_sync));
> }
>
> u32 drm_add_display_info(struct drm_connector *connector, const struct edid *edid)
> @@ -4975,6 +5017,8 @@ u32 drm_add_display_info(struct drm_connector *connector, const struct edid *edi
>
> info->non_desktop = !!(quirks & EDID_QUIRK_NON_DESKTOP);
>
> + drm_get_adaptive_sync_range(connector, edid);
> +
> DRM_DEBUG_KMS("non_desktop set to %d\n", info->non_desktop);
>
> if (edid->revision < 3)
> diff --git a/include/drm/drm_connector.h b/include/drm/drm_connector.h
> index 0df7a95ca5d9..2b22c0fa42c4 100644
> --- a/include/drm/drm_connector.h
> +++ b/include/drm/drm_connector.h
> @@ -254,6 +254,23 @@ enum drm_panel_orientation {
> DRM_MODE_PANEL_ORIENTATION_RIGHT_UP,
> };
>
> +/**
> + * struct drm_adaptive_sync_info - Panel's Adaptive Sync capabilities for
> + * &drm_display_info
> + *
> + * This struct is used to store a Panel's Adaptive Sync capabilities
> + * as parsed from EDID's detailed monitor range descriptor block.
> + *
> + * @min_vfreq: This is the min supported refresh rate in Hz from
> + * EDID's detailed monitor range.
> + * @max_vfreq: This is the max supported refresh rate in Hz from
> + * EDID's detailed monitor range
> + */
> +struct drm_adaptive_sync_info {
> + u8 min_vfreq;
> + u8 max_vfreq;
> +};
> +
> /*
> * This is a consolidated colorimetry list supported by HDMI and
> * DP protocol standard. The respective connectors will register
> @@ -473,6 +490,11 @@ struct drm_display_info {
> * @non_desktop: Non desktop display (HMD).
> */
> bool non_desktop;
> +
> + /**
> + * @adaptive_sync: Adaptive Sync capabilities of the DP/eDP sink
> + */
> + struct drm_adaptive_sync_info adaptive_sync;
> };
>
> int drm_display_info_set_bus_formats(struct drm_display_info *info,