Ubuntu Feisty and IDE (pata) drives
Saturday, May 12th, 2007One thing that buggs me about Ubuntu Feisty (yes, some things do 
) is that it didn’t recognise my cdroms (ide, secondary bus).
Apart from an inability to use the drives, and lshw that stalled when reading IDE, the only hint was a ‘hdc: lost interrupt’ that dmesg spewed after having correctly identified the drives. This particular bug also stopped the Feisty live CD from booting.
After much googleing and even more frustration, the solution seems to be to add ‘irqpoll’ to the default kernel line in /boot/grub/menu.lst. irqpoll seems to be a workaround for some bizarre kernel bugs, in any case for me it worked in fixing my install (I haven’t yet checked it on the live cd, so YMMV).
The bug itself seems to stem from the unified disk model present in the kernel 2.6.20 which handles scsi and sata a treat, but has some problems with legacy pata systems.