On Fri, 19 Aug 2022, Ville Syrjala <ville.syrjala@xxxxxxxxxxxxxxx> wrote: > From: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx> > > EDID 1.4 introduced some extra flags in the range > descriptor to support min/max h/vfreq >= 255. Consult them > to correctly parse the vfreq limits. > > Cc: stable@xxxxxxxxxxxxxxx > Closes: https://gitlab.freedesktop.org/drm/intel/-/issues/6519 > Signed-off-by: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx> > --- > drivers/gpu/drm/drm_edid.c | 24 ++++++++++++++++++------ > include/drm/drm_edid.h | 5 +++++ > 2 files changed, 23 insertions(+), 6 deletions(-) > > diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c > index 90a5e26eafa8..4005dab6147d 100644 > --- a/drivers/gpu/drm/drm_edid.c > +++ b/drivers/gpu/drm/drm_edid.c > @@ -6020,12 +6020,14 @@ static void drm_parse_cea_ext(struct drm_connector *connector, > } > > static > -void get_monitor_range(const struct detailed_timing *timing, > - void *info_monitor_range) > +void get_monitor_range(const struct detailed_timing *timing, void *c) > { > - struct drm_monitor_range_info *monitor_range = info_monitor_range; > + struct detailed_mode_closure *closure = c; > + struct drm_display_info *info = &closure->connector->display_info; > + struct drm_monitor_range_info *monitor_range = &info->monitor_range; > const struct detailed_non_pixel *data = &timing->data.other_data; > const struct detailed_data_monitor_range *range = &data->data.range; > + const struct edid *edid = closure->drm_edid->edid; > > if (!is_display_descriptor(timing, EDID_DETAIL_MONITOR_RANGE)) > return; > @@ -6041,18 +6043,28 @@ void get_monitor_range(const struct detailed_timing *timing, > > monitor_range->min_vfreq = range->min_vfreq; > monitor_range->max_vfreq = range->max_vfreq; > + > + if (edid->revision >= 4) { > + if (data->pad2 & DRM_EDID_RANGE_OFFSET_MIN_VFREQ) > + monitor_range->min_vfreq += 255; > + if (data->pad2 & DRM_EDID_RANGE_OFFSET_MAX_VFREQ) > + monitor_range->max_vfreq += 255; > + } Nitpick, a combo where min vertical range has +255 offset but max doesn't shouldn't be okay. But then, what are we going to do in that case anyway? I guess the generic check would be min <= max. Also, the +255 offset range is 256..510, not 256..(255+255). Again, what to do if that's what the EDID has? *shrug*. Anyway, what's broken here (and probably impacts the testing in the referenced bug) is that the struct drm_monitor_range_info members are u8 and this overflows. With that fixed, whether or not you decide to do anything about the nitpicks, Reviewed-by: Jani Nikula <jani.nikula@xxxxxxxxx> Side note, git grep for monitor_range reveals amdgpu are doing their own thing for the parsing. *sigh*. > } > > static void drm_get_monitor_range(struct drm_connector *connector, > const struct drm_edid *drm_edid) > { > - struct drm_display_info *info = &connector->display_info; > + const struct drm_display_info *info = &connector->display_info; > + struct detailed_mode_closure closure = { > + .connector = connector, > + .drm_edid = drm_edid, > + }; > > if (!version_greater(drm_edid, 1, 1)) > return; > > - drm_for_each_detailed_block(drm_edid, get_monitor_range, > - &info->monitor_range); > + drm_for_each_detailed_block(drm_edid, get_monitor_range, &closure); > > DRM_DEBUG_KMS("Supported Monitor Refresh rate range is %d Hz - %d Hz\n", > info->monitor_range.min_vfreq, > diff --git a/include/drm/drm_edid.h b/include/drm/drm_edid.h > index 2181977ae683..d81da97cad6e 100644 > --- a/include/drm/drm_edid.h > +++ b/include/drm/drm_edid.h > @@ -92,6 +92,11 @@ struct detailed_data_string { > u8 str[13]; > } __attribute__((packed)); > > +#define DRM_EDID_RANGE_OFFSET_MIN_VFREQ (1 << 0) > +#define DRM_EDID_RANGE_OFFSET_MAX_VFREQ (1 << 1) > +#define DRM_EDID_RANGE_OFFSET_MIN_HFREQ (1 << 2) > +#define DRM_EDID_RANGE_OFFSET_MAX_HFREQ (1 << 3) > + > #define DRM_EDID_DEFAULT_GTF_SUPPORT_FLAG 0x00 > #define DRM_EDID_RANGE_LIMITS_ONLY_FLAG 0x01 > #define DRM_EDID_SECONDARY_GTF_SUPPORT_FLAG 0x02 -- Jani Nikula, Intel Open Source Graphics Center
