libata: add qc_fill_rtf port operation

On command completion, ata_qc_complete() directly called ops->tf_read
to fill qc->result_tf.  This patch adds ops->qc_fill_rtf to replace
hardcoded ops->tf_read usage.

ata_sff_qc_fill_rtf() which uses ops->tf_read to fill result_tf is
implemented and set in ata_base_port_ops and other ops tables which
don't inherit from ata_base_port_ops, so this patch doesn't introduce
any behavior change.

ops->qc_fill_rtf() is similar to ops->sff_tf_read() but can only be
called when a command finishes.  As some non-SFF controllers don't
have TF registers defined unless they're associated with in-flight
commands, this limited operation makes life easier for those drivers
and help lifting SFF assumptions from libata core layer.

Signed-off-by: Tejun Heo <htejun@gmail.com>

1 files changed, 2 insertions, 1 deletions

diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c
index 51876b93c1b7..3b822124e97e 100644
--- a/drivers/ata/libata-core.c
+++ b/drivers/ata/libata-core.c
@@ -74,6 +74,7 @@ const unsigned long sata_deb_timing_hotplug[]		= {  25,  500, 2000 };
 const unsigned long sata_deb_timing_long[]              = { 100, 2000, 5000 };
 
 const struct ata_port_operations ata_base_port_ops = {
+        .qc_fill_rtf            = ata_sff_qc_fill_rtf,
         .prereset               = ata_std_prereset,
         .postreset              = ata_std_postreset,
         .error_handler          = ata_std_error_handler,
@@ -4562,7 +4563,7 @@ static void fill_result_tf(struct ata_queued_cmd *qc)
         struct ata_port *ap = qc->ap;
 
         qc->result_tf.flags = qc->tf.flags;
-        ap->ops->sff_tf_read(ap, &qc->result_tf);
+        ap->ops->qc_fill_rtf(qc);
 }
 
 static void ata_verify_xfer(struct ata_queued_cmd *qc)