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

Mario Kleiner
2020-03-06T18:53:03Z

Just as a comment, u8 for max_vfreq in struct drm_adaptive_sync_info
might be not very future proof?

I just read that ASUS announced a "TUF Gaming VG259QM" monitor which
seems to have an adaptive sync range of 48 Hz to 280 Hz, exceeding the
max 255 Hz of u8?

-mario

On Fri, Mar 6, 2020 at 4:02 PM Kazlauskas, Nicholas
<nicholas.kazlauskas@amd.com> wrote:
>
> 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,
> >
>
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