[PATCH] ACPI: do not warn if _BQC does not exist

[PATCH] ACPI: do not warn if _BQC does not exist

[Zhang Rui]

>From da38c4f4decae22797aa39d5ac8518cada0302e3 Mon Sep 17 00:00:00 2001
From: Zhang Rui <rui.zhang@intel.com>
Date: Tue, 29 Nov 2016 16:13:56 +0800
Subject: [PATCH] ACPI: do not warn if _BQC does not exist

Starting from ACPI spec 3.0, it's only clarified that _BCM control
method is required if _BCL is implemented. There is no word
saying _BQC is required.

And in ACPI spec 6.1 B.5.4, for _BQC, it is explicitly stated that
"This optional method returns the current brightness level of a
built-in display output device. If present, it must be set by
the platform for initial brightness."

Thus remove the obsolete warning message.

Signed-off-by: Zhang Rui <rui.zhang@intel.com>
---
 drivers/acpi/scan.c | 3 ---
 1 file changed, 3 deletions(-)

diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c
index 3d1856f..07aa2e6 100644
--- a/drivers/acpi/scan.c
+++ b/drivers/acpi/scan.c
@@ -1119,9 +1119,6 @@ acpi_backlight_cap_match(acpi_handle handle, u32 level, void *context,
 		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found generic backlight "
 				  "support\n"));
 		*cap |= ACPI_VIDEO_BACKLIGHT;
-		if (!acpi_has_method(handle, "_BQC"))
-			printk(KERN_WARNING FW_BUG PREFIX "No _BQC method, "
-				"cannot determine initial brightness\n");
 		/* We have backlight support, no need to scan further */
 		return AE_CTRL_TERMINATE;
 	}
-- 
2.7.4

Re: [PATCH] ACPI: do not warn if _BQC does not exist

[Rafael J. Wysocki]

On Tuesday, November 29, 2016 04:30:05 PM Zhang Rui wrote:
> From da38c4f4decae22797aa39d5ac8518cada0302e3 Mon Sep 17 00:00:00 2001
> From: Zhang Rui <rui.zhang@intel.com>
> Date: Tue, 29 Nov 2016 16:13:56 +0800
> Subject: [PATCH] ACPI: do not warn if _BQC does not exist
> 
> Starting from ACPI spec 3.0, it's only clarified that _BCM control
> method is required if _BCL is implemented. There is no word
> saying _BQC is required.
> 
> And in ACPI spec 6.1 B.5.4, for _BQC, it is explicitly stated that
> "This optional method returns the current brightness level of a
> built-in display output device. If present, it must be set by
> the platform for initial brightness."
> 
> Thus remove the obsolete warning message.
> 
> Signed-off-by: Zhang Rui <rui.zhang@intel.com>

Applied.

Thanks,
Rafael