From mboxrd@z Thu Jan 1 00:00:00 1970 From: akpm@linux-foundation.org Subject: [patch for 2.6.29? 1/1] acer-wmi: fix regression in backlight detection Date: Wed, 04 Mar 2009 12:07:34 -0800 Message-ID: <200903042007.n24K7Yc7029496@imap1.linux-foundation.org> Return-path: Received: from smtp1.linux-foundation.org ([140.211.169.13]:53524 "EHLO smtp1.linux-foundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757510AbZCDU0m (ORCPT ); Wed, 4 Mar 2009 15:26:42 -0500 Sender: linux-acpi-owner@vger.kernel.org List-Id: linux-acpi@vger.kernel.org To: lenb@kernel.org Cc: linux-acpi@vger.kernel.org, akpm@linux-foundation.org, mspang@csclub.uwaterloo.ca, ak@linux.intel.com, carlos@strangeworlds.co.uk, len.brown@intel.com, rjw@sisk.pl, rui.zhang@intel.com, stable@kernel.org, trenn@suse.de From: Michael Spang Currently we disable the Acer WMI backlight device if there is no ACPI backlight device. As a result, we end up with no backlight device at all. We should instead disable it if there is an ACPI device, as the other laptop drivers do. This regression was introduced in febf2d9 ("Acer-WMI: fingers off backlight if video.ko is serving this functionality"). Each laptop driver with backlight support got a similar change around febf2d9. The changes to the other drivers look correct; see e.g. a598c82f for a similar but correct change. The regression is also in 2.6.28. Signed-off-by: Michael Spang Cc: Thomas Renninger Cc: Zhang Rui Cc: Andi Kleen Cc: Carlos Corbacho Cc: Len Brown Cc: "Rafael J. Wysocki" Cc: [2.6.28.x] Signed-off-by: Andrew Morton --- drivers/platform/x86/acer-wmi.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff -puN drivers/platform/x86/acer-wmi.c~acer-wmi-fix-regression-in-backlight-detection drivers/platform/x86/acer-wmi.c --- a/drivers/platform/x86/acer-wmi.c~acer-wmi-fix-regression-in-backlight-detection +++ a/drivers/platform/x86/acer-wmi.c @@ -1297,7 +1297,7 @@ static int __init acer_wmi_init(void) set_quirks(); - if (!acpi_video_backlight_support() && has_cap(ACER_CAP_BRIGHTNESS)) { + if (acpi_video_backlight_support() && has_cap(ACER_CAP_BRIGHTNESS)) { interface->capability &= ~ACER_CAP_BRIGHTNESS; printk(ACER_INFO "Brightness must be controlled by " "generic video driver\n"); _