Bug 56661
| Summary: | Framebuffer on boot causes brightness to go to minimum on HP laptop | ||
|---|---|---|---|
| Product: | ACPI | Reporter: | Dan Dart (dandart) |
| Component: | Power-Video | Assignee: | Lan Tianyu (tianyu.lan) |
| Status: | CLOSED CODE_FIX | ||
| Severity: | low | CC: | aaron.lu, ashwillis, daniel, intel-gfx-bugs, tianyu.lan |
| Priority: | P1 | ||
| Hardware: | All | ||
| OS: | Linux | ||
| Kernel Version: | any | Subsystem: | |
| Regression: | No | Bisected commit-id: | |
| Attachments: |
dmesg
A patch to enable the backlight on startup on HP Pavilion g6 laptops |
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(In reply to comment #0) > Caused when going into framebuffer for the first time on boot. Would that be when the i915 driver is loaded? Please provide dmesg all the way from boot with drm.debug=0xe module parameter. dmesg content: https://gist.github.com/dandart/5398812 The actual resetting appears to be on line 711 with: [ 9.867926] [drm:intel_panel_actually_set_backlight], set backlight PWM = 0 after two tries to get the i2c dp_aux_ch status (707-710): [ 9.865314] [drm:intel_dp_aux_ch], dp_aux_ch timeout status 0x5143003f [ 9.865321] [drm:intel_dp_i2c_aux_ch], aux_ch failed -110 [ 9.867860] [drm:intel_dp_aux_ch], dp_aux_ch timeout status 0x5143003f [ 9.867866] [drm:intel_dp_i2c_aux_ch], aux_ch failed -110 Is this sufficient to take a stab at the cause? Cheers Dan Created attachment 98941 [details] dmesg dmesg from comment #2 (In reply to comment #3) > dmesg from comment #2 Hmm, only realized now that this is running 3.2 kernel. Please attach dmesg running a more recent kernel. Dan, please attach dmesg running a more recent kernel. Here we are with a 3.9 kernel from git (close to defconfig tbh so might be a little off): https://gist.github.com/dandart/5498460 Created attachment 102371 [details]
A patch to enable the backlight on startup on HP Pavilion g6 laptops
Hi Dan, I've got a g6 and it's exhibiting the same behaviour. I'm assuming when you say the backlight is on its minimum setting, you mean it's completely turned off? That's the behaviour I'm seeing anyway.
You're right. It seems that there is something up with the HP bios. It does not correctly report its previous brightness setting so the driver makes the mistake of 'resuming' it to 0 on initialisation. Please find the attached patch which will disable the bios check and instead set it to maximum brightness.
A more elegant fix would be to determine how to get some sense out of the bios but at least this patch should enable the displays of g6 users.
Cheers,
Ash
Since we can quirk this in the acpi driver, it must be an acpi bug ;-) Thanks, the patch works on 3.10-rc1 from git. Hi Ash:
Your patch in the comment7 fixs this bug and so please send it to acpi maillist.
Thanks for testing, Dan. Lan, I've forwarded this patch to the acpi list as requested :) Patch has sent to ACPI maillist. https://patchwork.kernel.org/patch/2627471/. commit 780a6ec640a3fed671fc2c40e4dd30c03eca3ac3 Author: Ash Willis <ashwillis.kernel@gmail.com> Date: Wed May 29 01:27:59 2013 +0000 ACPI / video: ignore BIOS initial backlight value for HP Pavilion g6 Commit upstream. acpidump please, I would like to see if it is the same firmware problem I've recently saw a lot and the following patch should quirk them all: http://www.spinics.net/lists/linux-acpi/msg47212.html And the patch to fix all these problems is: commit 2c62333a408f5badd2d2ffd7177f95deeccc5ca4 Author: Aaron Lu <aaron.lu@intel.com> Date: Wed Nov 6 09:07:10 2013 +0800 ACPI / video: Quirk initial backlight level 0 It is now in Rafael's linux-next branch: http://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm.git Please kindly give it a test, thanks. For easy testing, I've prepared a branch for you: https://github.com/aaronlu/linux acpi_video_dmi It is based on Rafael's linux-next branch(thus it already has the above mentioned fix patch), with only one patch on top: Remove the affected system from the DMI table to test if the above mentioned fix patch can work for it. |
Hi, FYI: On my Pavilion G6 going into framebuffer causes the screen to dim to lowest brightness setting. I can manually increase it after this time using the buttons if I install the modules (which all distros bundle). Caused when going into framebuffer for the first time on boot. Resolves itself sometimes when going into X. product: HP Pavilion g6 Notebook PC (A9W47EA#ABU) Display section of lshw: *-display description: VGA compatible controller product: 2nd Generation Core Processor Family Integrated Graphics Controller vendor: Intel Corporation physical id: 2 bus info: pci@0000:00:02.0 version: 09 width: 64 bits clock: 33MHz capabilities: msi pm vga_controller bus_master cap_list rom configuration: driver=i915 latency=0 resources: irq:42 memory:c0000000-c03fffff memory:b0000000-bfffffff ioport:4000(size=64) Not a regression afaik as I've always noticed it. Low priority as easily worked around (just confusing why it happens). Happens on any kernel (ubuntu, debian, homebuilt up to 3.6 - not tested on 3.7+). Cheers