linux-2.6.6 hdc: lost interrupt

I've just been patching our computers to the 2.6.6 kernel. One of them was no problem but the other...when I rebooted into the new kernel it would always hang probing the cdrom with the message

ide-cd: cmd 0x5a timed out
hdc: lost interrupt

I recompiled the kernel dozens of times with many different combinations of options and none of them made any difference. The solution came to me when I rebooted into the 2.6.5 kernel and typed dmesg into the terminal and there on the screen was a message I'd seen so many times that I'd stopped seeing it...

PCI: Using ACPI for IRQ routing
PCI: if you experience problems, try using option 'pci=noacpi' or even 'acpi=off'

So I tried booting with the option pci=noacpi in /boot/grub/menu.lst and it worked first time. I've recompiled with my current best config for this machine and it's all working again. The only thing I'm left wondering about is what changed between the 2.6.5 and 2.6.6 kernels that doesn't agree with the DVD/CDRW in this machine? It's working though, so I won't be losing sleep over it.

I experienced the same problem yesterday after compiling 2.6.6. It wasn't just by cd drive but two of my hard drives that were flagging this error message. I recompiled several times even doing a line by line comparison to my 2.6.5 and 2.6.1 configurations. I think there is a new ide option (generic ide ??) can't remember off the top of my head. I also did some searching on Google this morning and the problem has been seen by a few other people. I'll give your workaround a try later and see how it goes.

I've the same problem

Have anobody have resolv this ?

did you try the pci=noacpi boot parameter?

after booting with that param, check dmesg for new messages and try some of the recommended options from there; if nothing works, use an older kernel

Originally posted by TheOneAndOnlySM did you try the pci=noacpi boot parameter?

I gave it a go yesterday and it worked fine. After some more googling, I found that this seems to be the common workaround for the problem.

Hi, newbie here, had the same probs myself on my new computer, simple solution I found... Updating my BIOS! I al using an Asrock K7S8X motherboard and I think that the old BIOS (2.20) was conflicting with something, with the new BIOS installed (2.30) all worked fine.

Hope this is of use to someone

Hello!
I have Asrock K7S8X motherboard, too, and the only way to install or start Mandrake 9.2 or 10 was option "linux noapic". But after updating bios to 2.30, there is no need for extra options in LILO. Thanks for you, mikejac69.

In the kernel options, I think there was an option on PCI access modes... and one of them was ACPI... so if you recompile the kernel with something that isn't ACPI, it might work.
Sorry if this seems disjointed, trying to remember something from a kernel coniguration program I don't have infront of me...