Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756197Ab2FYLuP (ORCPT ); Mon, 25 Jun 2012 07:50:15 -0400 Received: from mail19.svc.cra.dublin.eircom.net ([159.134.118.218]:43665 "HELO mail19.svc.cra.dublin.eircom.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1756079Ab2FYLuO (ORCPT ); Mon, 25 Jun 2012 07:50:14 -0400 X-Greylist: delayed 398 seconds by postgrey-1.27 at vger.kernel.org; Mon, 25 Jun 2012 07:50:14 EDT From: Dave Airlie To: len.brown@intel.com, torvalds@linuxfoundation.org, linux-kernel@vger.kernel.org Cc: Igor Murzov , stable@vger.kernel.org, Zhang Rui Subject: Still use ACPI backlight control if _DOS doesn't exist Date: Mon, 25 Jun 2012 12:38:56 +0100 Message-Id: <1340624336-15048-1-git-send-email-airlied@redhat.com> X-Mailer: git-send-email 1.7.10.2 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1522 Lines: 46 This is a regression introduced by commit ea9f8856bd6d4ed45885b06a338f7362cd6c60e5 https://bugzilla.kernel.org/show_bug.cgi?id=43168 Some platforms don't have _DOS control method, but the ACPI backlight still works. We do not want to lose the backlight control ability on these platforms. [airlied: this is breaking nouveau really badly on 3.4 and after and there is no movement on sending it upstream, so please apply] Cc: Igor Murzov Cc: stable@vger.kernel.org Cc: len.brown@intel.com Signed-off-by: Zhang Rui --- drivers/acpi/video.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) Index: rtd3/drivers/acpi/video.c =================================================================== --- rtd3.orig/drivers/acpi/video.c +++ rtd3/drivers/acpi/video.c @@ -565,8 +565,14 @@ acpi_video_bus_DOS(struct acpi_video_bus video->dos_setting = arg0.integer.value; status = acpi_evaluate_object(video->device->handle, "_DOS", &args, NULL); - if (ACPI_FAILURE(status)) - return -EIO; + if (ACPI_FAILURE(status)) { + /* + * some platforms don't have _DOS, but the ACPI + * backlight control still works + */ + ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No _DOS\n")); + return 0; + } return 0; } -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/