Re: i915 black screen introduced by ACPI changes

From: Chris Li
Date: Wed Feb 20 2013 - 02:17:41 EST

On Tue, Feb 19, 2013 at 12:52 PM, Jesse Barnes <jbarnes@xxxxxxxxxxxxxxxx> wrote:
> Well it definitely sounds i915 related. I was just thinking that if
> certain bits were routed to the nvidia chip instead of the i915 one,
> the i915 driver may get confused and panic.

That is certainly possible.

> For debugging, you could modify the modeset_init function in i915_dma.c
> and make it return early with an error. You could use that to narrow
> down which part of init was failing.

I did try that. It seems there is not fail at modeset_init function. The
function complete successfully. Here is the related section.
[i915 Hack] was the line add by me.

There is one line said: "vgaarb: transferring owner from
PCI:0000:00:02.0 to PCI:0000:01:00.0".
Does it mean the display switch to the Nvidia video card?

[ 4.917591] i915 0000:00:02.0: setting latency timer to 64
[ 4.962649] i915 0000:00:02.0: irq 43 for MSI/MSI-X
[ 4.962656] [drm] Supports vblank timestamp caching Rev 1 (10.10.2010).
[ 4.962660] [drm] Driver supports precise vblank timestamp query.
[ 4.962663] [i915 Hack] enter modeset
[ 4.962670] [i915 Hack] after intel_parse_bios
[ 4.962672] [i915 Hack] after vga_client_register
[ 4.962727] [i915 Hack] after intel_register_dsm_handler
[ 4.962730] [i915 Hack] after intel_switchroo_register_client
[ 4.962733] [i915 Hack] after i915_gen_init_stolen
[ 4.962752] vgaarb: device changed decodes:
[ 4.962757] vgaarb: transferring owner from PCI:0000:00:02.0 to
[ 5.018486] [i915 Hack] after intel_modeset_init
[ 5.020823] [i915 Hack] after i915_gem_init
[ 5.020869] [i915 Hack] after intel_modeset_gem_init
[ 5.020892] [i915 Hack] after drm_irq_install
[ 5.051980] fbcon: inteldrmfb (fb0) is primary device
[ 5.089303] psmouse serio1: synaptics: Touchpad model: 1, fw: 8.1,
id: 0x1e2b1, caps: 0xd00123/0x840300/0x123c00, board id: 1800, fw id:
[ 5.202472] input: SynPS/2 Synaptics TouchPad as
[ 5.711448] Console: switching to colour frame buffer device 240x67
[ 5.722628] i915 0000:00:02.0: fb0: inteldrmfb frame buffer device
[ 5.722630] i915 0000:00:02.0: registered panic notifier
[ 5.722633] [i915 Hack] after intel_fbdev_init
[ 5.722634] [i915 Hack] after drm_kms_helper_poll_init
[ 5.722635] [i915 Hack] exit mode switch
[ 5.722682] nouveau 0000:01:00.0: enabling device (0006 -> 0007)
[ 5.723017] [Firmware Bug]: ACPI(PEGP) defines _DOD but not _DOS
[ 5.733222] acpi device:3c: registered as cooling_device8
[ 5.733587] ACPI: Video Device [PEGP] (multi-head: yes rom: yes post: no)
[ 5.733746] input: Video Bus as
[ 5.745904] acpi device:48: registered as cooling_device9

I attach the dmesg and config of the kernel. It is with the tip of git tree.

BTW, my previous claim was wrong about the kernel is dead. It turn out the
wifi is usable after the black screen, I just need to wait long
enough. The kernel
has no panic at all. That explains why I didnot get a kernel crash
dump previously.
The caps locks LED actually works.



Attachment: dmesg
Description: Binary data

Attachment: .config
Description: Binary data