> I guess that bit doesn't really make any difference with remotely modern > drives, then.. Could we make that ata_id_has_dword_io check always > return true if ata_id_is_ata returns true and only check word 48 if not? I suspect (but need to dig further) that ata_id_has_dword_io should only be called by pata_legacy. > I saw Willy Tarreau's patch from February for this, I agree that we > should likely use a separate data_xfer method for 32-bit transfer (or if > enough controllers should support 32-bit, then just make it be the > default and make a separate 16-bit only function for those that don't), > rather than punting the decision to the user with hdparm. Definitely. > You mentioned in the thread for Willy's patch that "some > controllers have quirky rules for 32bit xfers" - any details anywhere? There are two main ones - Some controllers only support 32bit I/O for a multiple of 32bit values [sometimes 'unless the fifo is disabled']. I'd have to go back over the docs but I think the AMD may be one of those - Some controllers (VLB generally) require a magic sequence before the transfer. You'll see that in the pata_legacy bits. Alan -- 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
