Tejun Heo writes: > Hello, > > Mikael Pettersson wrote: > > The problem is still present in 2.6.29-rc2. > > > > More debugging first showed that only the specific machine mentioned > > above is affected, as I've tested -rc1 on several other ata_piix boxes > > with various oldish disks and cdroms and none of the others triggered > > the hang. > > > > Secondly, the hang is due to the HP CD-Writer drive as having only it > > on the second port suffices to produce the hang. It doesn't matter if > > it's configured as master or slave. > > > > In any event, this shows that using 32-bit I/O ops should also be a > > function of the drive you're talking to, not just the controller. > > If you connect the writer to another machine, does it make the machine > hang too? I haven't tried it since that machine is at a different geographical location from my other machines. But I can try it next weekend. My hang goes away with Hugh Dickins' fix for ata_sff_data_xfer32 [1] which fixed a CD-ROM error (not hang) on his ata_piix box, and his patch also fixed a CD-ROM error on a another person's pata_ali box [2]. The patch changes ata_sff_data_xfer32 to use 16-bit PIO instead of 32-bit on any 1/2/3 byte "slop" after the main payload. But Alan thinks that AMD chipsets cannot handle that [3]. (One of my test boxes is an old AMD-chipset Athlon, I can test both my problematic CD-writer and the possibly AMD-incompatible fix on it next weekend.) [1] <http://marc.info/?l=linux-kernel&m=123254501314058&w=2> [2] <http://marc.info/?l=linux-ide&m=123277213928172&w=2> [3] <http://marc.info/?l=linux-kernel&m=123257958112434&w=2> /Mikael -- To unsubscribe from this list: send the line "unsubscribe linux-ide" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
