On Sat, 28 Dec 2002, Alvin Oga wrote: Drifiting to hardware issues...
I'm trying hard to get a better grasp of this stuff -- short of reading ATA and PCI specs! I don't really understand the difference between PIO modes and DMA settings, for one thing. I also have no idea what all these settings do in real life -- especially for reasonably slow CD drives. I suppose that can't all be explained in a few paragraphs, though. Ok, so I guess it makes sense to enable the fastest mode that's available on *both* the IDE controller and the drive. And in this case the Intel PIIXn chipset is UDMA/33 and so is the Plextor CD-R. So I should set the -X66 flag to select UDMA mode 2. Any idea how that setting works? Does hdparm send a flag to the kernel IDE subsystem to enable udma mode 2, which knows to set a bit in the IDE chipset (e.g. in this case UDMACTL at offset 48h bit 2 for the secondary interface drive 0). Or is it just telling the drive to go in that mode and we hope that the IDE chipset is enabled for udma mode 2 as well? And if that's the case, how does the IDE chipset get enabled for that mode? BTW - I also notice that the hard drive on this machine is also not set the best: /dev/hda: multcount = 16 (on) I/O support = 0 (default 16-bit) unmaskirq = 0 (off) using_dma = 1 (on) keepsettings = 0 (off) nowerr = 0 (off) readonly = 0 (off) readahead = 8 (on) geometry = 1662/255/63, sectors = 26712000, start = 0 busstate = 1 (on) I wonder if the kernel IDE controller for the PIIXn chipset can't be a bit more verbose on how it's configuring the drives. When I get a chance I'll take your advice and disable everything not related in the kernel and see if that fixes things. I also notice this message: ide: Assuming 33MHz system bus speed for PIO modes; override with idebus=xx Is that the PCI bus speed to the IDE controller? How do I track down if that can indeed be set differently? Thanks, -- Bill Moseley [EMAIL PROTECTED] -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of "unsubscribe". Trouble? Contact [EMAIL PROTECTED]
