Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754107Ab3COKLJ (ORCPT ); Fri, 15 Mar 2013 06:11:09 -0400 Received: from mout.web.de ([212.227.17.12]:50758 "EHLO mout.web.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753282Ab3COKLI (ORCPT ); Fri, 15 Mar 2013 06:11:08 -0400 From: Danny Baumann To: linux-acpi@vger.kernel.org Cc: linux-kernel@vger.kernel.org, Zhang Rui , Len Brown , Danny Baumann Subject: [PATCH v2 1/3] ACPI video: Fix brightness control initialization for some laptops. Date: Fri, 15 Mar 2013 11:10:46 +0100 Message-Id: <1363342248-6496-1-git-send-email-dannybaumann@web.de> X-Mailer: git-send-email 1.8.1.4 X-Provags-ID: V02:K0:urpPtPey7XNz51emYmMIuYfAkgVijXDrXg3rZNbs/34 DfwwboboqRWPm3vO8H6BUngCoKpBHkfAwLlCCTUwQg5hvmBeyX eIrIoWEal7vi4ekE+jGIn4QvDZoDtyUiETV13fp8MbKGYhOuqv m/s/yzcPb8bx86+l3HdbUaiMQgqHp2Ps4cHI5P7/n1x8hJ0Fje GGDHBVG2P/Z3wk3d5tlRg== Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4044 Lines: 106 In particular, this fixes brightness control initialization for all devices that return index values from _BQC and don't happen to have the initial index set by the BIOS in their _BCL table. One example for that is the Dell Inspiron 15R SE (model number 7520). What happened for those devices is that acpi_init_brightness queried the initial brightness by calling acpi_video_device_lcd_get_level_current. This called _BQC, which returned e.g. 13. As _BQC_use_index isn't determined at this point (and thus has its initial value of 0), the index isn't converted into the actual level. As '13' isn't present in the _BCL list, *level is later overwritten with brightness->curr, which was initialized to max_level (100) before. Later in acpi_init_brightness, level_old (with the value 100) is used as an index into the _BCL table, which causes a value outside of the actual table to be used as input into acpi_video_device_lcd_set_level(). Depending on the (undefined) value of that location, this call will fail, causing the brightness control for the device in question not to be enabled. Fix that by returning the raw value returned by the _BQC call in the initialization case. Signed-off-by: Danny Baumann --- drivers/acpi/video.c | 33 ++++++++++++++++++++------------- 1 file changed, 20 insertions(+), 13 deletions(-) diff --git a/drivers/acpi/video.c b/drivers/acpi/video.c index 313f959..9c33871 100644 --- a/drivers/acpi/video.c +++ b/drivers/acpi/video.c @@ -222,7 +222,7 @@ static int acpi_video_device_lcd_set_level(struct acpi_video_device *device, int level); static int acpi_video_device_lcd_get_level_current( struct acpi_video_device *device, - unsigned long long *level, int init); + unsigned long long *level, int raw); static int acpi_video_get_next_level(struct acpi_video_device *device, u32 level_current, u32 event); static int acpi_video_switch_brightness(struct acpi_video_device *device, @@ -452,7 +452,7 @@ static struct dmi_system_id video_dmi_table[] __initdata = { static int acpi_video_device_lcd_get_level_current(struct acpi_video_device *device, - unsigned long long *level, int init) + unsigned long long *level, int raw) { acpi_status status = AE_OK; int i; @@ -463,6 +463,15 @@ acpi_video_device_lcd_get_level_current(struct acpi_video_device *device, status = acpi_evaluate_integer(device->dev->handle, buf, NULL, level); if (ACPI_SUCCESS(status)) { + if (raw) { + /* + * Caller has indicated he wants the raw + * value returned by _BQC, so don't furtherly + * mess with the value. + */ + return 0; + } + if (device->brightness->flags._BQC_use_index) { if (device->brightness->flags._BCL_reversed) *level = device->brightness->count @@ -476,16 +485,14 @@ acpi_video_device_lcd_get_level_current(struct acpi_video_device *device, device->brightness->curr = *level; return 0; } - if (!init) { - /* - * BQC returned an invalid level. - * Stop using it. - */ - ACPI_WARNING((AE_INFO, - "%s returned an invalid level", - buf)); - device->cap._BQC = device->cap._BCQ = 0; - } + /* + * BQC returned an invalid level. + * Stop using it. + */ + ACPI_WARNING((AE_INFO, + "%s returned an invalid level", + buf)); + device->cap._BQC = device->cap._BCQ = 0; } else { /* Fixme: * should we return an error or ignore this failure? @@ -714,7 +721,7 @@ acpi_video_init_brightness(struct acpi_video_device *device) if (result) goto out_free_levels; - result = acpi_video_device_lcd_get_level_current(device, &level, 0); + result = acpi_video_device_lcd_get_level_current(device, &level, 1); if (result) goto out_free_levels; -- 1.8.1.4 -- 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/