4.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Patrik Jakobsson <patrik.r.jakobsson@xxxxxxxxx> commit 82bc9a42cf854fdf63155759c0aa790bd1f361b0 upstream. With LVDS we were incorrectly picking the pre-programmed mode instead of the prefered mode provided by VBT. Make sure we pick the VBT mode if one is provided. It is likely that the mode read-out code is still wrong but this patch fixes the immediate problem on most machines. Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=78562 Signed-off-by: Patrik Jakobsson <patrik.r.jakobsson@xxxxxxxxx> Link: http://patchwork.freedesktop.org/patch/msgid/20170418114332.12183-1-patrik.r.jakobsson@xxxxxxxxx Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/gpu/drm/gma500/psb_intel_lvds.c | 18 +++++++++++------- 1 file changed, 11 insertions(+), 7 deletions(-) --- a/drivers/gpu/drm/gma500/psb_intel_lvds.c +++ b/drivers/gpu/drm/gma500/psb_intel_lvds.c @@ -783,20 +783,23 @@ void psb_intel_lvds_init(struct drm_devi if (scan->type & DRM_MODE_TYPE_PREFERRED) { mode_dev->panel_fixed_mode = drm_mode_duplicate(dev, scan); + DRM_DEBUG_KMS("Using mode from DDC\n"); goto out; /* FIXME: check for quirks */ } } /* Failed to get EDID, what about VBT? do we need this? */ - if (mode_dev->vbt_mode) + if (dev_priv->lfp_lvds_vbt_mode) { mode_dev->panel_fixed_mode = - drm_mode_duplicate(dev, mode_dev->vbt_mode); + drm_mode_duplicate(dev, dev_priv->lfp_lvds_vbt_mode); - if (!mode_dev->panel_fixed_mode) - if (dev_priv->lfp_lvds_vbt_mode) - mode_dev->panel_fixed_mode = - drm_mode_duplicate(dev, - dev_priv->lfp_lvds_vbt_mode); + if (mode_dev->panel_fixed_mode) { + mode_dev->panel_fixed_mode->type |= + DRM_MODE_TYPE_PREFERRED; + DRM_DEBUG_KMS("Using mode from VBT\n"); + goto out; + } + } /* * If we didn't get EDID, try checking if the panel is already turned @@ -813,6 +816,7 @@ void psb_intel_lvds_init(struct drm_devi if (mode_dev->panel_fixed_mode) { mode_dev->panel_fixed_mode->type |= DRM_MODE_TYPE_PREFERRED; + DRM_DEBUG_KMS("Using pre-programmed mode\n"); goto out; /* FIXME: check for quirks */ } }