Re: 2.4.20, 2.4.22, 2.4.6-test7: system locks up completely whenwriting to floppy (2.2.20 is ok) - solution

From: Andriy Rysin
Date: Fri Oct 17 2003 - 13:26:10 EST


Andriy Rysin wrote:

I've got two motherboards on which I have this problem, they're ASUS P4S533-X and P4S533-MX. When I am trying to write something to a floppy the system hangs completely. dd, mkfs or mount + cp are all the sme. The floppy does several writing sounds and that's it, the light is on. No oppses, no panic no log/console messages. I have this with 2.4.20, 2.4.22 both from RedHat and 2.4.6-test7 from http://people.redhat.com/arjanv/2.5/RPMS.kernel/
I don't have this with DOS :) or linux 2.2.20 from tomsrtbt floppy and I don't have this on any other motherboards.
I changed floppy, changed floppy cable, tried different BIOS settings, changed video card, changed hardrives, booted in S mode. Reproducible 100%.
It seems pretty like this message http://www.uwsg.iu.edu/hypermail/linux/kernel/0202.2/1557.html
dmesg from 2.4.22 is below.
Please CC me if you reply or need more info.

Ok, I've tested kernels from 2.4.0 to 2.4.22 and found that it's a CONFIG_APM_CPU_IDLE=y which causes machine to hang. It seems like on ASUS P4533 motherboards this option is unsafe so it must be turned off. In RedHat kernels they turned on it after 2.4.18 that's why I saw the hangs. Actually the option help says that some machine may hang and probably it should not be on by default. Luckily I was able to fix that adding "apm=idle_threshold=100" to the kernel parameters without recompiling the kernel.
Maybe these motherboards/BIOS should be blacklisted?

Andriy

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