From: Mark Lord <liml@rtr.ca>
Date: Mon, 2 Apr 2007 20:20:35 +0000 (-0400)
Subject: 2.6.21 fix lba48 bug in libata fill_result_tf()
X-Git-Tag: v2.6.21-rc6~16^2~5
X-Git-Url: http://git.rot13.org/?a=commitdiff_plain;h=4742d54fa4b391342dfb8f34de14d51da101fb39;p=powerpc.git

2.6.21 fix lba48 bug in libata fill_result_tf()

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>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
---

diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c
index ddb3909d72..e07142b4bb 100644
--- a/drivers/ata/libata-core.c
+++ b/drivers/ata/libata-core.c
@@ -4717,8 +4717,8 @@ 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;
+	ap->ops->tf_read(ap, &qc->result_tf);
 }
 
 /**