UbiquitousOS
/
OpenCloudOS-Kernel
mirror of https://gitee.com/OpenCloudOS/OpenCloudOS-Kernel.git
11
0
Fork 0
Code Issues Projects Releases Wiki Activity

drm/i915: Fix not finding the VBT when it overlaps with OPREGION_ASLE_EXT 

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
This commit is contained in:
Hans de Goede 2017-02-14 18:12:38 +02:00 committed by Jani Nikula
parent 4ac9659ef9
commit dfb65e71ea
1 changed files with 12 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

13
drivers/gpu/drm/i915/intel_opregion.c
View File

@ -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;