This is a note to let you know that I've just added the patch titled drm/gma500/psb: Actually use VBT mode when it is found to the 4.4-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: drm-gma500-psb-actually-use-vbt-mode-when-it-is-found.patch and it can be found in the queue-4.4 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From 82bc9a42cf854fdf63155759c0aa790bd1f361b0 Mon Sep 17 00:00:00 2001 From: Patrik Jakobsson <patrik.r.jakobsson@xxxxxxxxx> Date: Tue, 18 Apr 2017 13:43:32 +0200 Subject: drm/gma500/psb: Actually use VBT mode when it is found 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 */ } } Patches currently in stable-queue which might be from patrik.r.jakobsson@xxxxxxxxx are queue-4.4/drm-gma500-psb-actually-use-vbt-mode-when-it-is-found.patch