libata: fix spurious WARN_ON_ONCE() on port freeze

Commit 54c38444fad6a99b4b19512f8f0055d69115e69e makes libata abort qcs
after the port is frozen.  This is necessary to guarantee that TF
registers are accessed after the DMA engine is shutdown after an
error.  However, this triggers WARN_ON_ONCE() check in
ata_qc_complete() spuriously.  Move WARN_ON_ONCE() downwards such that
failing commands while frozen doesn't trigger it.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: stable <stable@kernel.org>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>

diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c
index df31deac5c8224fce9e4e0571c4484d35d966966..0ddaf43d68c68dd89e2b36409487bf57b5f54686 100644 (file)
--- a/drivers/ata/libata-core.c
+++ b/drivers/ata/libata-core.c
@@ -5024,8 +5024,6 @@ void ata_qc_complete(struct ata_queued_cmd *qc)
                struct ata_device *dev = qc->dev;
                struct ata_eh_info *ehi = &dev->link->eh_info;
 
-               WARN_ON_ONCE(ap->pflags & ATA_PFLAG_FROZEN);
-
                if (unlikely(qc->err_mask))
                        qc->flags |= ATA_QCFLAG_FAILED;
 
@@ -5038,6 +5036,8 @@ void ata_qc_complete(struct ata_queued_cmd *qc)
                        }
                }
 
+               WARN_ON_ONCE(ap->pflags & ATA_PFLAG_FROZEN);
+
                /* read result TF if requested */
                if (qc->flags & ATA_QCFLAG_RESULT_TF)
                        fill_result_tf(qc);