Better or advised configuration approach for Optimus based systems

[Gianluca Cecchi]

Hello,
I have an Asus U36SD laptop, with Optimus technology.
I'm not sure if my current approach is the correct/more safe one.
I think more and more devices are going to have this technology, so
this could be a cue to address future F17 potential users problems

At the moment I have F16 x86_64 on it and I'm planning to reserve a
partition for upcoming F17 tests.
So I would like to get an advise on best current approach for
configuring such systems in Linux in general, but in Fedora in
particular.

Some items requesting for comments, also in terms of Fedora decisions
if already taken/discussed

- my current hw config
# lspci -vnnn|grep -i vga
00:02.0 VGA compatible controller [0300]: Intel Corporation 2nd
Generation Core Processor Family Integrated Graphics Controller
[8086:0126] (rev 09) (prog-if 00 [VGA controller])
01:00.0 VGA compatible controller [0300]: nVidia Corporation Device
[10de:1050] (rev ff) (prog-if ff)

- I disabe Nvidia discrete card with acpi_call kernel module.
as described by Michal Kottman in a 2010 thread (I think it is still true):
"Optimus does not work on Linux (yet). Meanwhile, you can save the
battery by using acpi_call to turn your (unused) discrete GPU off."

So I'm using his acpi-call_240611.orig.tar.gz from ironhide (I have to
check new versions), putting in /etc/rc.d/rc.local
#!/bin/bash
echo "Disabling Nvidia video adapter..." | tee -a /var/log/nvida_disabled.log
/sbin/modprobe acpi_call
echo '\_SB.PCI0.PEG0.GFX0.DOFF' > /proc/acpi/call

- Also, I boot with the parameter
i915.i915_enable_rc6=1

My current boot command line is
cat /proc/cmdline
BOOT_IMAGE=/boot/vmlinuz-3.1.1-2.fc16.x86_64
root=UUID=ce058d6c-d2ed-49e5-9869-965799f246a5 ro rd.md=0 rd.lvm=0
rd.dm=0 KEYTABLE=us quiet SYSFONT=latarcyrheb-sun16 rhgb rd.luks=0
LANG=en_US.UTF-8 i915.i915_enable_rc6=1 elevator=deadline

What about i915_enable_rc6 not being the default...? Does still put
stability problems? Does it make sense to enable it or not by default
based on different adapters/chipsets?
In my case it gives me about 1hour and a half of battery life more....

- What should I do with nouveau kernel module?
Should I put inside boot option also something like nouveau.nomodeset=0 ?
At this time I have nouveau loaded, but nvidida adapter disabled (with
acpi_call)
$ sudo lsmod | grep nouv
nouveau               580663  0
ttm                    55029  1 nouveau
drm_kms_helper         26490  2 nouveau,i915
drm                   194476  6 nouveau,ttm,i915,drm_kms_helper
i2c_algo_bit            4958  2 nouveau,i915
mxm_wmi                 1727  1 nouveau
i2c_core               25728  7
videodev,i2c_i801,nouveau,i915,drm_kms_helper,drm,i2c_algo_bit
video                  12388  2 nouveau,i915

- Right now I'm just using  the 2.17.0 Xorg intel driver, shipped as
an update today in Fedora 16
Based on this page it should have many bug fixes and improvements:
http://www.phoronix.com/scan.php?page=news_item&px=MTAxNjU

BTW: is the Intel driver in Fedora 16 currently built with
"--enable-sna" option or planned to be ?


So if there are any advises regarding the points above, I will try and
follow them for both F16 and upcoming F17 tests.

Thanks in advance for your time.

Gianluca