Resolution problem with Sabayon revisited [Solved]

[dunsurfin]

This was my original thread: viewtopic.php?f=53&t=23479

Intel video, on a Dell studio 17 with Pentium Dual CPU T3400 @ 2.16GHz 3 GB and Wide Screen display 1440x900 LDVS.

As with other kernels since 2.6.35, booting SL 6 x86K live DVD gives me a resolution of 1024x768 that cannot be changed to the correct 1440x900. Adding the refresh and resolution to the boot parameters makes no difference. I have today tried two other live DVDs/CDs. Possibly the closest to SL is the gentoo live DVD 11. It only has kernel 2.6.37 but it boots perfectly at 1440x900. The other distro was PClinux OS minime with kernel 2.6.38.8. That booted at 1024x768 but allowed me to alter it to 1440x900 without any trouble.

It seems to me that there is something different in the SL kernel since version 2.6.35 that is the root of this problem. Unfortunately I have no idea where to look for the problem and which logs would be important. If someone will advise on the information required I shall attempt to access it.

[Fitzcarraldo]

I can't tell you how to fix it, but I can tell you how I would investigate it:

You could compare the kernel config for the Sabayon 2.6.35 kernel with the kernel config for the Ubuntu 2.6.38-r3 kernel that you mentioned works in your other thread. I don't think the config file for the Sabayon 2.6.35 kernel is still in the Sabayon repository, so you'd have to use the zcat command to get it from your running installation (see SL Wiki article HOWTO: Upgrade kernel using genkernel for how to use that command). The config for the latest Sabayon kernel (2.6.39-r7) is in the SL Git repository: [linux/kernel/sabayon.git]/sabayon/config/. I don't know off hand how to get the sources for the Ubuntu 2.6.38-r3 kernel, but it's explained in the Ubuntu Community Documentation page https://help.ubuntu.com/community/Kerne ... l%20source (alternatively you could use the zcat command on a running Ubuntu installation to get the config for the Ubuntu kernel, in the same way as for your SL 2.6.35 kernel installation).

Unfortunately, these things are a real PITA to analyse.

[dunsurfin]

Eek!
Thank you for that Fitzcarraldo. I shall scratch my head for a day or two and then see what I can find out. Would it not make sense to compare the Gentoo 2.6.37 with the SL 2.6.37 as I have the 2.6.37 still on the machine (albeit in broken resolution) and I have the Gentoo 2.6.37 on the live DVD?
The learning curves here are perpendicular!

[Fitzcarraldo]

Would it not make sense to compare the Gentoo 2.6.37 with the SL 2.6.37 as I have the 2.6.37 still on the machine (albeit in broken resolution) and I have the Gentoo 2.6.37 on the live DVD?

Sure, if one works and the other doesn't.

[dunsurfin]

In the end, the answer was so simple I still don't quite believe it. After peering at several thousand lines in 3 different configs and finding nothing unusual I went back to first principles and looked at the logs again and then at xorg.conf. The "generic monitor" setting had a VertRefresh of 43 - 60 and I remembered that the optimum refresh rate for my laptop is 60.8. So I changed the VertRefresh to 43 - 61 and it works. I now have the correct resolution. Thanks to everyone who has helped with this and previous thread.

[Fitzcarraldo]

Well, look at it on the bright side: By comparing the kernels' config files you were able to rule out the kernel as a probable cause of the problem. Anyway, it's good to read you finally cracked it.

[dunsurfin]

I look on it all as a good learning experience.

[dunsurfin]

Just to add that the same problem appeared installing SLK 8 x86 (dated 12/2/12). So if anyone is struggling with trying to get the correct resolution on a Dell Studio 17 all you need to do is open /etc/x11/xorg.conf and change

Code: Select all

VertRefresh    43 - 60

to

Code: Select all

VertRefresh    43 - 61

and reboot.