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>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c
index 3d1856f..07aa2e6 100644 (file)
--- 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;
        }