[PATCH 1/2] libata EH: freeze port before aborting commands

From: Jeff Garzik
Date: Tue Apr 07 2009 - 19:23:03 EST



commit 9c2fd3d1955572d3d1ee596b5f81c9768dde896e
Author: Jeff Garzik <jeff@xxxxxxxxxx>
Date: Tue Apr 7 19:13:15 2009 -0400

[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@xxxxxxxxxx>

---
Alan, we should create ata_sff_bmdma_freeze() and use that to turn off
the PCI IDE BMDMA engine in ->freeze(), too, I think...


diff --git a/drivers/ata/libata-eh.c b/drivers/ata/libata-eh.c
index 0183131..b79cbd6 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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