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.
(In reply to comment #0) This bug is also present on normal gentoo kernel >= 2.6.34.
In that case I'm reassigning this bug to the kernel team.
Have you tried: acpi_backlight=vendor as a kernel parameter?
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.