Dell laptops

[Bruno Ducrot]

Hi Eric,

On Tue, Jul 11, 2006 at 01:27:50PM -0500, Eric Anderson wrote:
> On 07/11/06 12:37, Anish Mistry wrote:
> >On Tuesday 11 July 2006 13:10, Daniel Eischen wrote:
> >>On Tue, 11 Jul 2006, M. Warner Losh wrote:
> >>>Greetings,
> >>>
> >>>What are the current problems, if any, on current Dell laptops
> >>>have with FreeBSD?
> >>Yeah, thanks for asking!  My Inspiron E1405 came with an Intel
> >>3945 A/B/G mini-PCI wireless that isn't supported (OpenBSD has
> >>a seemingly actively maintained wpi driver for this card, and
> >>I have an experimental FreeBSD driver from damien that I haven't
> >>yet been able to get to work).  I've ordered an Atheros-based
> >>mini-PCI in the meantime, and can lend out the 3945 to anyone
> >>willing to work on it.
> >>
> >>Also, the Fn (the blue key) can't be used to suspend, control
> >>volume, switch CRT/LCD, etc, and most importantly enable the
> >>radio on the wireless card (Fn + F2).  Even if the wpi driver
> >>works, it's worthless if I can't enable the radio.
> >It might simply need an acpi function keys driver for your system.  
> >Would you post an "acpidump -dt" from your system?
> >
> 
> 
> I have a bunch of info on the D820 posted here:
> 
> http://www.googlebit.com/freebsd/200607110621/

It has been useful for me.  Thanks.

First, this information confirm one bug present in all Dell laptops
I'm aware of (including but not limited to D600, D610, inspiron 6000)
The bug is ACPI related, and concern how a particular event is
handled.  To be short, the ASL contain this method (example for
the D820):

    Method (SMIE, 0, NotSerialized)
    {
        Store (SMI (0x96, 0x00), Local0)
        If (And (Local0, 0x01))
        {
            Notify (\_TZ.THM, 0x80)
        }

        Notify (\_SB.PCI0.VID, 0x81)
        Notify (\_SB.PCI0.AGP.VID, 0x81)
    }

    If (And (Local0, 0x02))
    {
        Store (SMI (0x6D, 0x00), Local0)   <--- BUG.  Local0 will
                                                change in
                                                that case!!!
        ...
        ...
    }

    If (And (Local0, 0x04))   <--- We may not have the correct value for
                                   Local0 in that case...
    {
        Notify (\_SB.BAT0, 0x81)
        Notify (\_SB.BAT1, 0x81)
    }

    If (And (Local0, 0x08))
    {
        Notify (\_PR.CPU0, 0x80)
        Notify (\_PR.CPU1, 0x80)
    }

    If (And (Local0, 0x10))
    {
        ...
        ...
    }
    ...

This method possibly can change in the middle the value of Local0
and in that case the other If() statements are broken.

This method is called in order to handle an SCI interrupt, specifically
by \GPE._L19() (it will call in fact NEVT() which may call NEVT()).

I don't know how to contact Dell in order to get that fixed.


Second, there is a method called \SMI(), taking 2 arguments and
returning a value.  This method will actually trigger a SMI handler
in order to perform almost all power management stuff, as for
example getting fan status, controlling fan speed, controlling
docking and so on.  There is a specific kernel module under linux
called i8k, that can be found here :
http://people.debian.org/~dz/i8k/
Even though I think this driver could have possibly "funny" effect
if ACPI is enabled under Linux (it will actually share the same
IO with the SMI() method, and that must be serialized for obvious
reason), looking onto that driver we learn for example that
SMI(0x25, 0) will likely return the FN key status for almost
all Dell Laptop.

Therefore it should be somewhat easy to write a simple ACPI
driver for Dell laptops, at least for FN key (if those still
don't work).

ATM I don't have time for writing such support.

Cheers,

-- 
Bruno Ducrot

--  Which is worse:  ignorance or apathy?
--  Don't know.  Don't care.