Am Montag, den 05.11.2012, 12:45 +0100 schrieb Stefan Nagy:
> Since I didn't encounter this problem before
> linux-image-3.6-trunk-amd64 I had a look at these settings on
> linux-image-3.2.0-4-amd64 with normal backlight brightness:
> 'acpi_video0' (brightness 0, actual_brightness 0),
> 'intel_backlight' (brightness 4882, actual_brightness 4882). So the
> difference between 3.2 and 3.6 seems to be that backlight brightness
> wasn't controlled by the ACPI driver but the device specific driver in
> 3.2.
I was having the same problem with linux-image-3.2.0-4-amd64 for some
time now, I guess since update 3.2.32-1.
However, this bug was fixed upstream. I tested the patch on top of
kernel v3.2.32-1 and it fixes the problem.
>From 117af51d695c78bfdf618a183664f0e9f3769b9a Mon Sep 17 00:00:00 2001
From: Zhang Rui <rui.zh...@intel.com>
Date: Sun, 2 Dec 2012 10:00:41 +0800
Subject: [PATCH] ACPI video: ignore BIOS initial backlight value for HP Folio
13-2000.
Or else the laptop will boot with a dimmed screen.
Signed-off-by: Zhang Rui <rui.zh...@intel.com>
---
drivers/acpi/video.c | 14 ++++++++++++++
1 file changed, 14 insertions(+)
diff --git a/drivers/acpi/video.c b/drivers/acpi/video.c
index 1e0a9e1..58bddd3 100644
--- a/drivers/acpi/video.c
+++ b/drivers/acpi/video.c
@@ -389,6 +389,12 @@ static int __init video_set_bqc_offset(const struct dmi_system_id *d)
return 0;
}
+static int video_ignore_initial_backlight(const struct dmi_system_id *d)
+{
+ use_bios_initial_backlight = 0;
+ return 0;
+}
+
static struct dmi_system_id video_dmi_table[] __initdata = {
/*
* Broken _BQC workaround http://bugzilla.kernel.org/show_bug.cgi?id=13121
@@ -433,6 +439,14 @@ static struct dmi_system_id video_dmi_table[] __initdata = {
DMI_MATCH(DMI_PRODUCT_NAME, "Aspire 7720"),
},
},
+ {
+ .callback = video_ignore_initial_backlight,
+ .ident = "HP Folio 13-2000",
+ .matches = {
+ DMI_MATCH(DMI_BOARD_VENDOR, "Hewlett-Packard"),
+ DMI_MATCH(DMI_PRODUCT_NAME, "HP Folio 13 - 2000 Notebook PC"),
+ },
+ },
{}
};
--
1.7.9.5
