Ack! On 4/27/07, Danny Kukawka <dkukawka@xxxxxxx> wrote:
Hi, currently the acpi video module export the backlight interface to sysfs also if acpi_video_device_lcd_query_levels() fails to read _BLC method (e.g. because the method is not available). In this case the userspace don't know which brightness level are supported and can't set a brightness level (echo return with: "write error: Invalid Argument"). This happend e.g. on a ASUS RF1 (correct supported by the asus-laptop module). The video module should not export the backlight interface if query _BLC fail, because you can't set anything from userspace and this make it useless. See also: http://bugzilla.kernel.org/show_bug.cgi?id=8375 Danny From: Danny Kukawka <dkukawka@xxxxxxx> Subject: ACPI video: Don't export sysfs backlight interface if query _BLC fail if qeuery _BCL fail (e.g. because the method is missing in BIOS) don't export the backlight interface to sysfs. Signed-off-by: Danny Kukawka <dkukawka@xxxxxxx> --- video.c | 78 ++++++++++++++++++++++++++++-------------------------- 1 file changed, 41 insertions(+), 37 deletions(-) --- linux-2.6.21/drivers/acpi/video.c 2007-04-26 13:50:51.000000000 +0200 +++ linux-2.6.21/drivers/acpi/video.c 2007-04-26 13:50:53.000000000 +0200 @@ -531,7 +531,6 @@
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