libata: relocate and fix post-command processing

Some commands need post-processing after successful completion.  This
was done in ata_scsi_qc_complete() till now but this has the following
problems.

* Post-command processing gets executed when qc is completed from EH.
  Some qc's are retried from EH with zero err_mask and thus triggers
  unnecessary/incorrect post-command processing.

* Command post processing doesn't belong to SAT layer.

* Link-wide revalidation was scheduled where device revalidation
  suffices.

This patch moves post-command processing to success completion path of
ata_qc_complete() which is travelled iff the command is going to be
completed without passing through EH and updates post-command
processing such that device-specific action is used.  While at it,
restructure code a bit for readability.

Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>

1 files changed, 20 insertions, 0 deletions

diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c
index 081e3dfb64d4..5aedd1af06e6 100644
--- a/drivers/ata/libata-core.c
+++ b/drivers/ata/libata-core.c
@@ -5594,6 +5594,9 @@ void ata_qc_complete(struct ata_queued_cmd *qc)
          * taken care of.
          */
         if (ap->ops->error_handler) {
+                struct ata_device *dev = qc->dev;
+                struct ata_eh_info *ehi = &dev->link->eh_info;
+
                 WARN_ON(ap->pflags & ATA_PFLAG_FROZEN);
 
                 if (unlikely(qc->err_mask))
@@ -5612,6 +5615,23 @@ void ata_qc_complete(struct ata_queued_cmd *qc)
                 if (qc->flags & ATA_QCFLAG_RESULT_TF)
                         fill_result_tf(qc);
 
+                /* Some commands need post-processing after successful
+                 * completion.
+                 */
+                switch (qc->tf.command) {
+                case ATA_CMD_SET_FEATURES:
+                        if (qc->tf.feature != SETFEATURES_WC_ON &&
+                            qc->tf.feature != SETFEATURES_WC_OFF)
+                                break;
+                        /* fall through */
+                case ATA_CMD_INIT_DEV_PARAMS: /* CHS translation changed */
+                case ATA_CMD_SET_MULTI: /* multi_count changed */
+                        /* revalidate device */
+                        ehi->dev_action[dev->devno] |= ATA_EH_REVALIDATE;
+                        ata_port_schedule_eh(ap);
+                        break;
+                }
+
                 __ata_qc_complete(qc);
         } else {
                 if (qc->flags & ATA_QCFLAG_EH_SCHEDULED)