This message is displayed 2 times in the dmesg output : [ 1.039683] ACPI: Using IOAPIC for interrupt routing [ 1.040313] [Firmware Bug]: ACPI: ACPI brightness control misses _BQC function ... [ 5.214540] dcdbas dcdbas: Dell Systems Management Base Driver (version 5.6.0-3.2) [ 5.221713] [Firmware Bug]: ACPI: ACPI brightness control misses _BQC function I have dell Studio XPS 1645 and a Debian sid OS. I can control the brightness level with the key shortcuts so I suspect it concerns the brightness sensor which is not enabled.
No, this is harmless. It just suggests that there is a firmware bug in the BIOS, which we already have a workaround. I assume everything works fine, right? please attach the acpidump of this laptop.
Created attachment 27464 [details] Acpi dump output
[Firmware Bug]: ACPI: ACPI brightness control misses _BQC function This is a rather poor error message. First, "ACPI" is duplicated, and second, it is not clear what the rest of the message really means. It probably should be more like "could not find required _BQC function" or "required _BQC function was not found" or "required _BQC function is missing"
patch with updated error message has been sent out. https://patchwork.kernel.org/patch/119841/
commit e9f74c489c9d4209946c04f29e7a724cb5537206 Author: Zhang Rui <rui.zhang@intel.com> Date: Fri Sep 3 10:08:50 2010 +0800 ACPI video: fix a poor warning message staged for upstream
shipped in linux-2.6.36-rc6-git2 closed