On Sul, 2005-08-21 at 02:31 +0900, Tejun Heo wrote: > My preference is toward unifying into single path as long as > performance penalty is acceptable for the sake of simplicity.
I don't think it is a big issue for ATA. The drive tends to take 10-15 seconds before it goes and whines at us, and it is hopefully not a fast path. > >> * SCSI EH entrance is not synchronized with polling tasks. > > > > > > Yes, this definitely needs fixing. > > > > Luckily the polling task is very rarely used, by normal users. The old IDE has this bug on reset paths too - and people do eventually hit it. > > - DMA errors should be handled by hueristics: If more than $N (3?) DMA > > errors happen in 15 minutes, > > * decrease SATA PHY speed. if speed cannot be decreased, > > * decrease UDMA xfer speed. if at UDMA0, switch to PIO4 > > * decrease PIO xfer speed. if at PIO3, complain, but continue Remember this means issuing a command to the drive before re-issuing the failed command. The old IDE also has serious problems with this as it ends up trying to issue a polling command from an IRQ racing its own timeout code. One good reason for the EH approach scsi takes of quiescing first and running in task context. - To unsubscribe from this list: send the line "unsubscribe linux-ide" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html
