diff options
| -rw-r--r-- | drivers/gpu/drm/i915/intel_opregion.c | 13 |
1 files changed, 12 insertions, 1 deletions
diff --git a/drivers/gpu/drm/i915/intel_opregion.c b/drivers/gpu/drm/i915/intel_opregion.c index f4429f67a4e3..4a862a358c70 100644 --- a/drivers/gpu/drm/i915/intel_opregion.c +++ b/drivers/gpu/drm/i915/intel_opregion.c @@ -982,7 +982,18 @@ int intel_opregion_setup(struct drm_i915_private *dev_priv) opregion->vbt_size = vbt_size; } else { vbt = base + OPREGION_VBT_OFFSET; - vbt_size = OPREGION_ASLE_EXT_OFFSET - OPREGION_VBT_OFFSET; + /* + * The VBT specification says that if the ASLE ext + * mailbox is not used its area is reserved, but + * on some CHT boards the VBT extends into the + * ASLE ext area. Allow this even though it is + * against the spec, so we do not end up rejecting + * the VBT on those boards (and end up not finding the + * LCD panel because of this). + */ + vbt_size = (mboxes & MBOX_ASLE_EXT) ? + OPREGION_ASLE_EXT_OFFSET : OPREGION_SIZE; + vbt_size -= OPREGION_VBT_OFFSET; if (intel_bios_is_valid_vbt(vbt, vbt_size)) { DRM_DEBUG_KMS("Found valid VBT in ACPI OpRegion (Mailbox #4)\n"); opregion->vbt = vbt; |