Re: [Intel-gfx] [PATCH 07/11] drm/edid: Use GTF2 for inferred modes

Jani Nikula
2022-09-02T12:26:07Z

On Sat, 27 Aug 2022, Ville Syrjala <ville.syrjala@linux.intel.com> wrote:
> From: Ville Syrjälä <ville.syrjala@linux.intel.com>
>
> For some resaon we only use the secondary GTF curve for the
> standard timings. Use it for inferred modes as well.
>
> Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
> ---
> drivers/gpu/drm/drm_edid.c | 35 ++++++++++++++++++++++++++++++++++-
> 1 file changed, 34 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c
> index 0c7cbe9b44f5..fed2bdd55c09 100644
> --- a/drivers/gpu/drm/drm_edid.c
> +++ b/drivers/gpu/drm/drm_edid.c
> @@ -3546,6 +3546,35 @@ static int drm_gtf_modes_for_range(struct drm_connector *connector,
> return modes;
> }
>
> +static int drm_gtf2_modes_for_range(struct drm_connector *connector,
> + const struct drm_edid *drm_edid,
> + const struct detailed_timing *timing)
> +{
> + int i, modes = 0;
> + struct drm_display_mode *newmode;
> + struct drm_device *dev = connector->dev;
> +
> + for (i = 0; i < ARRAY_SIZE(extra_modes); i++) {
> + const struct minimode *m = &extra_modes[i];
> +
> + newmode = drm_gtf2_mode(dev, drm_edid, m->w, m->h, m->r);
> + if (!newmode)
> + return modes;
> +
> + drm_mode_fixup_1366x768(newmode);
> + if (!mode_in_range(newmode, drm_edid, timing) ||
> + !valid_inferred_mode(connector, newmode)) {
> + drm_mode_destroy(dev, newmode);
> + continue;
> + }
> +
> + drm_mode_probed_add(connector, newmode);
> + modes++;
> + }
> +
> + return modes;
> +}
> +
> static int drm_cvt_modes_for_range(struct drm_connector *connector,
> const struct drm_edid *drm_edid,
> const struct detailed_timing *timing)
> @@ -3594,7 +3623,11 @@ do_inferred_modes(const struct detailed_timing *timing, void *c)
> return; /* GTF not defined yet */
>
> switch (range->flags) {
> - case DRM_EDID_SECONDARY_GTF_SUPPORT_FLAG: /* XXX could do more */
> + case DRM_EDID_SECONDARY_GTF_SUPPORT_FLAG:
> + closure->modes += drm_gtf2_modes_for_range(closure->connector,
> + closure->drm_edid,
> + timing);
> + break;
> case DRM_EDID_DEFAULT_GTF_SUPPORT_FLAG:

Additionally, per spec:

* Default GTF supported if bit 0 in Feature Support Byte at address 18h = 1

* Secondary GTF supported --- requires support for Default GTF

So I guess both of these would need the edid->features &
DRM_EDID_FEATURE_DEFAULT_GTF check?

Other than that,

Reviewed-by: Jani Nikula <jani.nikula@intel.com>

> closure->modes += drm_gtf_modes_for_range(closure->connector,
> closure->drm_edid,

--
Jani Nikula, Intel Open Source Graphics Center