Bug 338760

Summary:	acpi set brightness to low during boot on HP envy 17 & 14
Product:	Gentoo Linux	Reporter:	lixo1
Component:	[OLD] Unspecified	Assignee:	Gentoo Kernel Bug Wranglers and Kernel Maintainers <kernel>
Status:	VERIFIED NEEDINFO
Severity:	normal	CC:	releng
Priority:	High
Version:	unspecified
Hardware:	All
OS:	Linux
URL:	https://bugzilla.kernel.org/show_bug.cgi?id=19342
Whiteboard:
Package list:		Runtime testing required:	---

Description lixo1 2010-09-26 09:15:52 UTC

Booting with gentoo option from the minimal CD installation on the HP envy 17 & 14, I observed that the screen brightness is modified to 0 when the ACPI is activated (saying [ok]).

If I use gentoo acpi=off, or gentoo acpi=ht, the problem disappears, but probably wifi, audio, etc... doesn't work anymore.

If you need further information please don't hesitate.

Reproducible: Always

Steps to Reproduce:
1. Download the lastest gentoo minimal CD version.
2. Boot with gentoo option, on a HP envy 17 or 14.
3. Wait for acpi activation.

Actual Results:  
After ACPI activation brightness goes to 0 value.

Expected Results:  
Brightness should not change.

Comment 1 lixo1 2010-11-01 22:41:37 UTC

(In reply to comment #0)
This bug is also present on normal gentoo kernel >= 2.6.34.

Comment 2 Jorge Manuel B. S. Vicetto (RETIRED) Gentoo Infrastructure

2010-12-01 18:18:22 UTC

In that case I'm reassigning this bug to the kernel team.

Comment 3 Mike Pagano gentoo-dev

2010-12-17 14:02:25 UTC

Have you tried: acpi_backlight=vendor as a kernel parameter?

Comment 4 lixo1 2011-01-01 23:02:53 UTC

This bug comes from a conflict between video acpi and HP envy Bios model when setting brightness to the initial value. It's a kernel/hp main tree issue.

There is a patch in test, available from the main kernel source, that will be applied in the future releases > 2.6.37.

So, I close this bug report. Thanks for your interest.