Hybrid ATI/ATI - Intel/ATI solution: small switcheroo how to

[paul!]

the only thing is that when you turn off the computer with one of the cards turned off; then, when you turn on the computer again the fan runs at full speed. So, to avoid this I also made a script "switch_before_shutdown.sh".

Since I switch off the discrete card during boot process (/etc/rc.d/c.local) the fan stays quiet.

cya

[rmartinez]

Since I switch off the discrete card during boot process (/etc/rc.d/c.local) the fan stays quiet.

cya

Thanks, it works great to avoid choosing every time the integrated card when the computer is initiated. So I did:

$ sudo gedit /etc/rc.d/rc.local

And added the following lines:

mount -t debugfs none /sys/kernel/debug
echo OFF > /sys/kernel/debug/vgaswitcheroo/switch

But even though it serves to avoid choosing the initial card configuration, it does not resolve the fan problem. I made some reboots and saw that the fan running at full speed only happens when I turn off the computer (not when rebooting) while having the integrated card ON and functioning, and the discrete card OFF. To avoid this I must be with the integrated card OFF and the discrete ON and functioning, or with both cards ON.

That is why I still need the script that before turning off the computer checks and turns ON both cards.

[Kano]

Why don't you mount debugfs in the fstab? Also whats the output of:

ls -l /sys/kernel/debug/vgaswitcheroo/switch

[rmartinez]

Why don't you mount debugfs in the fstab?

Yes, that could be a good alternative. Thanks.

Also whats the output of:

ls -l /sys/kernel/debug/vgaswitcheroo/switch

-rw-r--r-- 1 root root 0 2010-03-05 09:03 /sys/kernel/debug/vgaswitcheroo/switch

Why?

[Kano]

Well when it would not be root:root but something in another group like video or so then you would not need root rights just in the correct group. It would be more logical to use root:video 664 or so.

[rmartinez]

Well when it would not be root:root but something in another group like video or so then you would not need root rights just in the correct group. It would be more logical to use root:video 664 or so.

Mmm... Good! I will try that and post after launch! Thanks.

[rmartinez]

Well when it would not be root:root but something in another group like video or so then you would not need root rights just in the correct group. It would be more logical to use root:video 664 or so.

I have been reading a little bit and I found this:

Mount options for debugfs
The debugfs file system is a pseudo file system, traditionally mounted on /sys/kernel/debug. There are no mount options. (*)

So, if there are no options to mount debugfs, how can I mount it so that it gives other permission? I got to mount it with fstab with this line:

 none /sys/kernel/debug debugfs default 0 0

But no matter what options I tested (other than "default"), it has always has same permissions. What I'm doing wrong? Or because it has no mounting options the default cannot be changed?

[Kano]

The permission/owner/groups are most likely set in the driver itself. Ask the author.

[rmartinez]

I got it!! With just this line added at rc.local you can then switch cards without being su:

chown "username" /sys/kernel/debug/vgaswitcheroo/switch

Now I'm almost there to make the "switch_between_cards.sh" utilizable to normal user without being su! I just have to find something to replace the "sudo killall -u 'username'" to logout...

[Kano]

That's a stupid hack but would work. Why not change the kernel code? Btw. do you know

kill -9 -1

Do not try as root!