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Splooshie123 n00b
Joined: 16 Apr 2012 Posts: 27
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Posted: Sat Nov 10, 2012 12:27 am Post subject: Intel graphics not working on Macbook Pro in EFI mode |
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Hello.
I have Gentoo installed on a Macbook Pro 6,2 which has integrated Intel graphics and a discrete Nvidia GPU.
Code: | $ lspci | grep VGA
00:02.0 VGA compatible controller: Intel Corporation Core Processor Integrated Graphics Controller (rev 18)
01:00.0 VGA compatible controller: NVIDIA Corporation GT216 [GeForce GT 330M] (rev a2) |
With BIOS emulation, the intel gpu isn't even activated (not listed in lspci). So I have to use EFI mode.
The Nvidia gpu works fine in BIOS and EFI mode with no problems.
In EFI mode, the intel gpu is available, but it doesn't work. I get a blank screen with a few graphical artifacts during the whole boot process until the nvidia card kicks in.
These are the relevant kernel parameters kernel parameters:
Code: | i915.lvds_channel_mode=2 i915.modeset=1 i915.lvds_use_ssc=0 |
Any way I can get it working? |
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Splooshie123 n00b
Joined: 16 Apr 2012 Posts: 27
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Posted: Sat Nov 10, 2012 7:05 am Post subject: |
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Fixed it.
I had to add this to my grub.cfg before the kernel is loaded:
Code: | outb 0x728 1
outb 0x710 2
outb 0x740 2
outb 0x750 0 |
The first 3 lines switch to the intel graphics and the last line powers down the nvidia card. I was using the nvidia card the whole time! That's why it didn't work.
The last line is optional. I was able to start X without it. However, powering down the discrete graphics reduces energy consumption by 10 watts (I think per hour. Powertop doesn't say). |
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