kern/145306: [acpi]: Can't change brightness on HP ProBook 4510s

David DEMELIER demelier.david at
Thu Jun 10 17:47:24 UTC 2010

2010/4/5 Dan Lukes <dan at>:
> Short summary for PR/145306:
> I asked the David to turn on ACPI debugging. There are some notification
> (so we know we got debugging output properly) but none of them are
> related to brightness keys.
> David DEMELIER wrote:
>>>> I added them and I got a big output in dmesg but still no message when pressing fn-keys.
>> No message at all, like I didn't do anything
> Then no good news. I can't help you. Your BIOS doesn't create the
> notification required by ACPI specification section B.7
> Your's acpidump show that the notification may be sent, but we know the
> prerequisites that's need to be fulfilled. It may be a initialisation of
> something or so.
> If you have older than lates version of system BIOS (e.g. F.12 revision)
> the upgrade may help:
> May be someone smarter may help better to you. You should save output of:
> 1. acpidump -dt
> 2. devinfo -vr
> 3. dmesg after boot with ACPI debugging turned on
> somewhere then send URL to the PR so anyone can read it.
> I'm sorry I have no better response to you ...
>                                        Dan


Just one information I noticed today : when booting without ACPI
enabled (it does not boot it stops at a certain point (can't
remember)) I can change the brightness so maybe there is a problem
between freebsd ACPI <-> the laptop screen ?


Demelier David

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