From 54c38444fad6a99b4b19512f8f0055d69115e69e Mon Sep 17 00:00:00 2001
From: Jeff Garzik <jeff@garzik.org>
Date: Tue, 7 Apr 2009 19:13:15 -0400
Subject: [libata] EH: freeze port before aborting commands

Call the ->freeze() hook before aborting qc's, because some hardware
requires special handling prior to accessing the taskfile registers
(for diagnosis/analysis/reset).  Most notably, hardware may wish to
disable the DMA engine or interrupts in the ->freeze() hook.

Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
---
 drivers/ata/libata-eh.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

(limited to 'drivers/ata')

diff --git a/drivers/ata/libata-eh.c b/drivers/ata/libata-eh.c
index 79711b64054b..9159abe5211c 100644
--- a/drivers/ata/libata-eh.c
+++ b/drivers/ata/libata-eh.c
@@ -999,7 +999,9 @@ static void __ata_port_freeze(struct ata_port *ap)
  *	ata_port_freeze - abort & freeze port
  *	@ap: ATA port to freeze
  *
- *	Abort and freeze @ap.
+ *	Abort and freeze @ap.  The freeze operation must be called
+ *	first, because some hardware requires special operations
+ *	before the taskfile registers are accessible.
  *
  *	LOCKING:
  *	spin_lock_irqsave(host lock)
@@ -1013,8 +1015,8 @@ int ata_port_freeze(struct ata_port *ap)
 
 	WARN_ON(!ap->ops->error_handler);
 
-	nr_aborted = ata_port_abort(ap);
 	__ata_port_freeze(ap);
+	nr_aborted = ata_port_abort(ap);
 
 	return nr_aborted;
 }
-- 
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