drm/gma500/psb: Actually use VBT mode when it is found

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@gmail.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170418114332.12183-1-patrik.r.jakobsson@gmail.com
[bwh: Backported to 3.2: adjust filename]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

diff --git a/drivers/staging/gma500/psb_intel_lvds.c b/drivers/staging/gma500/psb_intel_lvds.c
index 21022e1..8e2afbb 100644 (file)
--- a/drivers/staging/gma500/psb_intel_lvds.c
+++ b/drivers/staging/gma500/psb_intel_lvds.c
@@ -792,20 +792,23 @@ void psb_intel_lvds_init(struct drm_device *dev,
                if (scan->type & DRM_MODE_TYPE_PREFERRED) {
                        mode_dev->panel_fixed_mode =
                            drm_mode_duplicate(dev, scan);
                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? */
                        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 =
                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
 
        /*
         * If we didn't get EDID, try checking if the panel is already turned


@@ -822,6 +825,7 @@ void psb_intel_lvds_init(struct drm_device *dev,
                if (mode_dev->panel_fixed_mode) {
                        mode_dev->panel_fixed_mode->type |=
                            DRM_MODE_TYPE_PREFERRED;
                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 */
                }
        }
                        goto out;       /* FIXME: check for quirks */
                }
        }