Re: [PATCH] 2.6.21 fix lba48 bug in libata fill_result_tf()

[Jeff Garzik <jgarzik@pobox.com>]

Mark Lord wrote:
> 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@pobox.com>

applied