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| author | Ville Syrjälä <ville.syrjala@linux.intel.com> | 2021-09-29 21:45:36 +0300 |
|---|---|---|
| committer | Ville Syrjälä <ville.syrjala@linux.intel.com> | 2021-09-30 11:20:40 +0300 |
| commit | f5b8c316092f2501ca32ac32f5c6303e2c58ef50 (patch) | |
| tree | 313a4b9bb6972f8279f3f3969b9b165f5e76c263 | |
| parent | cff4c2c645cbb3e95d7aec9afb1a803dd2668ec7 (diff) | |
| download | linux-f5b8c316092f2501ca32ac32f5c6303e2c58ef50.tar.gz linux-f5b8c316092f2501ca32ac32f5c6303e2c58ef50.tar.bz2 linux-f5b8c316092f2501ca32ac32f5c6303e2c58ef50.zip | |
drm/i915: Reject user modes that don't match fixed mode's refresh rate
When using a panel with a fixed mode we don't change the refresh
rate of the display. Reject any user requested mode which doesn't
match that fixed refresh rate.
Unfortunately when Xorg sees the scaling_mode property on the
connecor it likes to automagically cook up modes whose refresh
rate is a fair bit off from the fixed refresh rate we use. So
we have to give it some extra latitude so that we don't start to
reject all of it.
v2: sDVO now uses intel_panel_compute_config() too
v3: Add a debug message to inform the user what happened
References: https://gitlab.freedesktop.org/drm/intel/-/issues/2939
References: https://gitlab.freedesktop.org/drm/intel/-/issues/3969
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210929184536.8332-1-ville.syrjala@linux.intel.com
| -rw-r--r-- | drivers/gpu/drm/i915/display/intel_panel.c | 15 |
1 files changed, 15 insertions, 0 deletions
diff --git a/drivers/gpu/drm/i915/display/intel_panel.c b/drivers/gpu/drm/i915/display/intel_panel.c index 77c1ca387de0..a0c8e43db5eb 100644 --- a/drivers/gpu/drm/i915/display/intel_panel.c +++ b/drivers/gpu/drm/i915/display/intel_panel.c @@ -53,6 +53,21 @@ int intel_panel_compute_config(struct intel_connector *connector, if (!fixed_mode) return 0; + /* + * We don't want to lie too much to the user about the refresh + * rate they're going to get. But we have to allow a bit of latitude + * for Xorg since it likes to automagically cook up modes with slightly + * off refresh rates. + */ + if (abs(drm_mode_vrefresh(adjusted_mode) - drm_mode_vrefresh(fixed_mode)) > 1) { + drm_dbg_kms(connector->base.dev, + "[CONNECTOR:%d:%s] Requested mode vrefresh (%d Hz) does not match fixed mode vrefresh (%d Hz)\n", + connector->base.base.id, connector->base.name, + drm_mode_vrefresh(adjusted_mode), drm_mode_vrefresh(fixed_mode)); + + return -EINVAL; + } + drm_mode_copy(adjusted_mode, fixed_mode); drm_mode_set_crtcinfo(adjusted_mode, 0); |