[PATCH 2/2] ACPI / video / i915: Remove ACPI backlight if firmware expects Windows 8

Matthew Garrett matthew.garrett at nebula.com
Wed Sep 11 01:45:41 PDT 2013

On Wed, 2013-09-11 at 11:45 +0300, Jani Nikula wrote:

> Before plunging forward, have you observed any difference between the
> boot modes? We have reports [1] that the backlight behaviour is
> different with UEFI vs. UEFI+CSM or legacy boot. So I'm wondering if the
> acpi_gbl_osi_data >= ACPI_OSI_WIN_8 check in patch 2/2 is the whole
> story.
> Further, if we tell the BIOS we're Windows 8 to use the tested BIOS code
> paths, what guarantees do we have of UEFI+CSM or legacy boots working?

We have no evidence of Windows behaving differently based on the exposed
firmware type.

Matthew Garrett <matthew.garrett at nebula.com>

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