Mark Lord wrote: >> On Michael's real old ata_piix, somehow the ERR bit is set on phantom >> device defeating our phantom device detection logic. We can relax >> phantom device condition but that increases the risk of misdetection on >> actual IDENTIFY errors. Any ideas how we can nicely work around this >> one? > .. > > Mmm.. I'm way out of the loop on this now, > so please pardon me suggesting things known not to work, but.. > > 1. Pay attention to ATA status register on this chipset? > Eg. if it has BUSY, or reads 0x7f, then don't IDENTIFY? > 2. Check for device signature before trying IDENTIFY? > 3. Try a r/w test on the data register first, to see if there's > really hardware attached to it? We already do 1, 2 and 3. The problem with phantom device is that the existent device on the channel replies to acesses to the other non-existent device and the NODEV_HINT detection is the last line of defense which successfully evades all the other mechanisms. And now we have this controller/device combination which successfully tricks it too. :-( -- tejun -- 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
