| From 114076cdd96cca3d0284c7cf7c86c7ce305e45e1 Mon Sep 17 00:00:00 2001 |
| From: Hans de Goede <hdegoede@redhat.com> |
| Date: Tue, 14 Feb 2017 18:12:38 +0200 |
| Subject: [PATCH] drm/i915: Fix not finding the VBT when it overlaps with |
| OPREGION_ASLE_EXT |
| |
| commit 998d75730b40afc218c059d811869abe9676b305 upstream. |
| |
| If there is no OPREGION_ASLE_EXT then a VBT stored in mailbox #4 may |
| use the ASLE_EXT parts of the opregion. Adjust the vbt_size calculation |
| for a vbt in mailbox #4 for this. |
| |
| This fixes the driver not finding the VBT on a jumper ezpad mini3 |
| cherrytrail tablet and on a ACER SW5_017 machine. |
| |
| Cc: stable@vger.kernel.org |
| Signed-off-by: Hans de Goede <hdegoede@redhat.com> |
| Signed-off-by: Jani Nikula <jani.nikula@intel.com> |
| Link: http://patchwork.freedesktop.org/patch/msgid/1487088758-30050-1-git-send-email-jani.nikula@intel.com |
| (cherry picked from commit dfb65e71ea2c1d97ac373cc0587dc60b3307581a) |
| Signed-off-by: Jani Nikula <jani.nikula@intel.com> |
| Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com> |
| |
| diff --git a/drivers/gpu/drm/i915/intel_opregion.c b/drivers/gpu/drm/i915/intel_opregion.c |
| index 7acbbbf97833..4534e4cadccf 100644 |
| --- a/drivers/gpu/drm/i915/intel_opregion.c |
| +++ b/drivers/gpu/drm/i915/intel_opregion.c |
| @@ -1031,7 +1031,18 @@ 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; |
| -- |
| 2.12.0 |
| |
