pata_atiixp: Audit notes on locking

Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>

diff --git a/drivers/ata/pata_atiixp.c b/drivers/ata/pata_atiixp.c
index 95ed3071a0a0a3d006a88eb13d5285fd4f838c50..9623f52955306d690ff7f78713ff24a7f6de08db 100644 (file)
--- a/drivers/ata/pata_atiixp.c
+++ b/drivers/ata/pata_atiixp.c
@@ -173,6 +173,9 @@ static void atiixp_set_dmamode(struct ata_port *ap, struct ata_device *adev)
  *
  *     When DMA begins we need to ensure that the UDMA control
  *     register for the channel is correctly set.
+ *
+ *     Note: The host lock held by the libata layer protects
+ *     us from two channels both trying to set DMA bits at once
  */
 
 static void atiixp_bmdma_start(struct ata_queued_cmd *qc)
@@ -199,6 +202,9 @@ static void atiixp_bmdma_start(struct ata_queued_cmd *qc)
  *
  *     DMA has completed. Clear the UDMA flag as the next operations will
  *     be PIO ones not UDMA data transfer.
+ *
+ *     Note: The host lock held by the libata layer protects
+ *     us from two channels both trying to set DMA bits at once
  */
 
 static void atiixp_bmdma_stop(struct ata_queued_cmd *qc)