Bug 222799

Summary:	>=kernel-2.6.23 sometimes do not boot with uvesafb - amd64
Product:	Gentoo Linux	Reporter:	amadeus.bit
Component:	[OLD] Core system	Assignee:	Michal Januszewski (RETIRED) <spock>
Status:	RESOLVED NEEDINFO
Severity:	major	CC:	kfm
Priority:	High
Version:	unspecified
Hardware:	AMD64
OS:	Linux
Whiteboard:
Package list:		Runtime testing required:	---
Bug Depends on:	247453
Bug Blocks:

Description amadeus.bit 2008-05-19 11:41:57 UTC

I followed the tutorial on the gentoo wiki to use uvesafb. But in nearly 40% of all boots the kernel hangs on the scheduler selection (resolution is still small, probably the point where uvesa would be loaded).
I can not find any hints in dmesg and logfiles. And I can not tell how to reproduce. It seems very randomly.
In addition, splashutils wont work for me as well. I do not get any error message, but the splash does not appear. Do not know if splashutils causes this problem, but with vesafb everything is fine.
If the boot was successful I do not have any further problems.   

Here the part of my old grub.conf (now I use 2.6.23-r9 with vesafb):
title=Gentoo Linux 2.6.25 Exp
root (hd0,0)
kernel /boot/kernel_25_exp root=/dev/sda3 video=uvesafb:1024x768-32@60,mtrr:3,ywrap splash=verbose,fadein,theme:Shodan CONSOLE=/dev/tty1
initrd (hd0,0)/boot/shodan-1024x768


Reproducible: Sometimes

Steps to Reproduce:
1. Build the kernel with the v86d ramdisk and activate uvesa in kernel features and grub config. Probably use splashutils
2. Boot the kernel
3. Have bad luck

Actual Results:  
The kernel hangs at the scheduler selection and does not react anymore. I have to reset my machine

Expected Results:  
boot as usual

I run an ~amd64 machine with intel quadcore, 4GB DDR2-800, nforce chipset and geforce 8800gtx.
I use splashutils, which wont work with uvesafb for me.
Gentoo is up to date

Comment 1 Michal Januszewski (RETIRED) gentoo-dev

2008-06-12 19:04:53 UTC

Could you please provide the output of fbset -i (when uvesafb works during boot)?  Could you also try emerging v86d with the 'debug' USE flag and running testvbe (please attach the output of this program).  And finally, could you maybe try to build uvesafb as a module and try loading it manually with modprobe a few times (you'll have to reboot after uvesafb is successfully loaded) to see whether it causes a hang this way as well?

Comment 2 RumpletonBongworth 2008-11-18 19:31:24 UTC

It seems that hrtricks (high-resolution preemption ticks) are to blame for this bug:

https://bugs.launchpad.net/linux/+bug/258381

Would the reporter please confirm as to whether the problem disappears in a 2.6.27.5 based kernel? In the meantime, I'm adding bug 247453 as a depend.

Comment 3 RumpletonBongworth 2008-11-18 20:57:47 UTC

Also, I've added a patch for 2.6.25 which the reporter may wish to test against the specific kernel he was using at the time that the bug was detected:

http://bugs.gentoo.org/attachment.cgi?id=172297&action=view