Re: Faulty MTRR setups in Toshiba laptops crash video drivers

[Mehmet Giritli <mehmet@giritli.eu>]

On Mon, 2009-11-02 at 18:06 -0600, Robert Hancock wrote:
> On 11/02/2009 10:28 AM, Mehmet Giritli wrote:
> > Hello all,
> >
> > On some laptops using ATI 3650HD radeon chipsets and 4GB ram (and may be
> > others as well), it is impossible to start any xserver due to (faulty?)
> > mtrr setups on the machine. The computer locks up or just gives an
> > unresponsive black screen. There are various drivers for radeon cards
> > and the crash occurs in all of these drivers in the very same way!
> >
> > This bug seems to occur mostly on Toshiba laptops with ATI graphic
> > cards. For some people, CONFIG_MTRR_SANITIZER seemed to cure the issue
> > but made no difference for many others like me.
> >
> > RadeonHD people seem to have problems in understanding the nature of
> > this bug. Please have a look at the threads:
> >
> > http://lists.opensuse.org/radeonhd/2009-05/msg00040.html
> >
> > and,
> >
> > http://bugs.freedesktop.org/show_bug.cgi?id=20645
> >
> > for problem reports and dev responses. RadeonHD devs suggest that some
> > laptops have weird mtrr setups and this must be fixed in the kernel code
> > and not the driver code.
> 
> Unfortunately I don't see enough details to be able to tell what lead 
> them to this conclusion. Can you post the output of:
> 
> lspci -vv
> cat /proc/mtrr

lspci -vv
http://bugzilla.kernel.org/attachment.cgi?id=23634

/proc/mtrr when 4GB installed
http://bugzilla.kernel.org/attachment.cgi?id=23632

/proc/mtrr when 2GB installed
http://bugzilla.kernel.org/attachment.cgi?id=23633

There is also a bug report that I opened a while back here:
http://bugzilla.kernel.org/show_bug.cgi?id=14054



> 
> >
> > Currently, the only way that could make the driver work is to reduce the
> > 4GB ram to 2GB.
> >
> > dmesg from my affected machine when it has 4GB ram installed can be
> > found here:
> >
> > http://bugzilla.kernel.org/attachment.cgi?id=22856
> >
> > Also, look at the report here:
> >
> > https://bugs.launchpad.net/ubuntu/+source/linux/+bug/341681
> >
> > in order to see how many people are being affected by this bug!
> >
> > Kind Regards,
> > M. Giritli
> >
> >
>