kernel-packages team mailing list archive

[Jani-nikula <1265544@xxxxxxxxxxxxxxxxxx>]

(In reply to comment #13)
> Daniel, 
> 
> I'm already running drm-intel-nightly which includes that commit.
> That particular hack does indeed run (see attached dmesg log at the
> beginning) but the panel is still blank. I saw the same hack at
> intel_dp_get_config, but in my machine intel_dp_get_config does not get
> called at all.
> 
> The culprit is clamping bpp from 24 to 18 bpp at intel_dp_compute_config.
> When the bpp clamping code is disabled and the panel runs at 24 bpp there
> are no more blank screen issues. 

Please try this on drm-intel-nightly, and report what the debug says:

diff --git a/drivers/gpu/drm/i915/intel_ddi.c b/drivers/gpu/drm/i915/intel_ddi.c
index 74749c6..dbc5a16 100644
--- a/drivers/gpu/drm/i915/intel_ddi.c
+++ b/drivers/gpu/drm/i915/intel_ddi.c
@@ -1491,6 +1491,10 @@ void intel_ddi_get_config(struct intel_encoder *encoder,
                break;
        }
 
+       DRM_DEBUG_KMS("encoder type %d, pipe_bpp %d, vbt.edp_bpp %d, ddi ctl %08x\n",
+                     encoder->type, pipe_config->pipe_bpp,
+                     dev_priv->vbt.edp_bpp, temp);
+
        if (encoder->type == INTEL_OUTPUT_EDP && dev_priv->vbt.edp_bpp &&
            pipe_config->pipe_bpp > dev_priv->vbt.edp_bpp) {
                /*

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You received this bug notification because you are a member of Kernel
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https://bugs.launchpad.net/bugs/1265544

Title:
  8086:0a16 [UX302LG] black screen on boot 3.12.0-7

Status in The Linux Kernel:
  Incomplete
Status in “linux” package in Ubuntu:
  Triaged

Bug description:
  Same description/workaround as
  https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1263015

  I tried both Enable CSM and non-CSM boot.

  ProblemType: Bug
  DistroRelease: Ubuntu 14.04
  Package: linux-image-3.12.0-7-generic 3.12.0-7.15
  ProcVersionSignature: Ubuntu 3.12.0-7.15-generic 3.12.4
  Uname: Linux 3.12.0-7-generic x86_64
  ApportVersion: 2.12.7-0ubuntu3
  Architecture: amd64
  Date: Thu Jan  2 09:59:33 2014
  HibernationDevice: RESUME=UUID=e6458b44-fdb9-4db5-8cac-40ee0bbf9cf6
  InstallationDate: Installed on 2013-12-31 (1 days ago)
  InstallationMedia: Ubuntu 14.04 LTS "Trusty Tahr" - Alpha amd64 (20131231)
  Lsusb:
   Bus 002 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub
   Bus 001 Device 004: ID 03eb:8a03 Atmel Corp.
   Bus 001 Device 003: ID 1bcf:2987 Sunplus Innovation Technology Inc.
   Bus 001 Device 002: ID 8087:07dc Intel Corp.
   Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
  MachineType: ASUSTeK COMPUTER INC. UX302LG
  ProcFB: 0 simple
  ProcKernelCmdLine: BOOT_IMAGE=/vmlinuz-3.12.0-7-generic.efi.signed root=/dev/mapper/ubuntu--vg-root ro recovery nomodeset
  RelatedPackageVersions:
   linux-restricted-modules-3.12.0-7-generic N/A
   linux-backports-modules-3.12.0-7-generic  N/A
   linux-firmware                            1.117
  SourcePackage: linux
  UpgradeStatus: No upgrade log present (probably fresh install)
  dmi.bios.date: 10/30/2013
  dmi.bios.vendor: American Megatrends Inc.
  dmi.bios.version: UX302LG.207
  dmi.board.asset.tag: ATN12345678901234567
  dmi.board.name: UX302LG
  dmi.board.vendor: ASUSTeK COMPUTER INC.
  dmi.board.version: 1.0
  dmi.chassis.asset.tag: No Asset Tag
  dmi.chassis.type: 10
  dmi.chassis.vendor: ASUSTeK COMPUTER INC.
  dmi.chassis.version: 1.0
  dmi.modalias: dmi:bvnAmericanMegatrendsInc.:bvrUX302LG.207:bd10/30/2013:svnASUSTeKCOMPUTERINC.:pnUX302LG:pvr1.0:rvnASUSTeKCOMPUTERINC.:rnUX302LG:rvr1.0:cvnASUSTeKCOMPUTERINC.:ct10:cvr1.0:
  dmi.product.name: UX302LG
  dmi.product.version: 1.0
  dmi.sys.vendor: ASUSTeK COMPUTER INC.

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