Tejun, Current 2.6.21 libata does the following: void ata_tf_read(struct ata_port *ap, struct ata_taskfile *tf) { struct ata_ioports *ioaddr = &ap->ioaddr; tf->command = ata_check_status(ap); ... if (tf->flags & ATA_TFLAG_LBA48) { iowrite8(tf->ctl | ATA_HOB, ioaddr->ctl_addr); tf->hob_feature = ioread8(ioaddr->error_addr); ... } } ... static void fill_result_tf(struct ata_queued_cmd *qc) { struct ata_port *ap = qc->ap; ap->ops->tf_read(ap, &qc->result_tf); qc->result_tf.flags = qc->tf.flags; } Based on this, those last two statements fill_result_tf() appear to me to be in the wrong order, in that the tf->flags are uninitialized at the point where tf_read() is invoked. So for lba48 commands, tf_read() won't be reading back the full lba48 register contents.. Correct? This patch corrects fill_result_tf() so that the flags get copied to result_tf before they are used by tf_read(). Signed-off-by: Mark Lord <mlord@xxxxxxxxx> --- --- linux/drivers/ata/libata-core.c.orig 2007-03-21 12:46:06.000000000 -0400 +++ linux/drivers/ata/libata-core.c 2007-04-02 16:16:28.000000000 -0400 @@ -4763,8 +4763,8 @@ { struct ata_port *ap = qc->ap; - ap->ops->tf_read(ap, &qc->result_tf); qc->result_tf.flags = qc->tf.flags; + ap->ops->tf_read(ap, &qc->result_tf); } /** - 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