From: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx> 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 Signed-off-by: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx> --- drivers/gpu/drm/i915/display/intel_panel.c | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/drivers/gpu/drm/i915/display/intel_panel.c b/drivers/gpu/drm/i915/display/intel_panel.c index 77c1ca387de0..8c1ea322502c 100644 --- a/drivers/gpu/drm/i915/display/intel_panel.c +++ b/drivers/gpu/drm/i915/display/intel_panel.c @@ -53,6 +53,15 @@ 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) + return -EINVAL; + drm_mode_copy(adjusted_mode, fixed_mode); drm_mode_set_crtcinfo(adjusted_mode, 0); -- 2.32.0
