[libata] pata_atiixp: add locking for parallel scanning

This is similar change as commit 60c3be3 for ata_piix host driver
and while pata_atiixp doesn't enable parallel scan yet the race
could probably also be triggered by requesting re-scanning of both
ports at the same time using SCSI sysfs interface.

[Ported to current tree without other patch dependancies by Alan Cox]

Original is
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
This one is
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>

diff --git a/drivers/ata/pata_atiixp.c b/drivers/ata/pata_atiixp.c
index f697b5b880d38aa5c031ee86c1a720d7cb6033a3..9ad3b4ce1ca5b3840047c62b229ff29111ece162 100644 (file)
--- a/drivers/ata/pata_atiixp.c
+++ b/drivers/ata/pata_atiixp.c
@@ -1,7 +1,7 @@
 /*
  * pata_atiixp.c       - ATI PATA for new ATA layer
  *                       (C) 2005 Red Hat Inc
- *                       (C) 2009 Bartlomiej Zolnierkiewicz
+ *                       (C) 2009-2010 Bartlomiej Zolnierkiewicz
  *
  * Based on
  *
@@ -46,6 +46,8 @@ static int atiixp_cable_detect(struct ata_port *ap)
        return ATA_CBL_PATA40;
 }
 
+static DEFINE_SPINLOCK(atiixp_lock);
+
 /**
  *     atiixp_set_pio_timing   -       set initial PIO mode data
  *     @ap: ATA interface
@@ -88,7 +90,10 @@ static void atiixp_set_pio_timing(struct ata_port *ap, struct ata_device *adev,
 
 static void atiixp_set_piomode(struct ata_port *ap, struct ata_device *adev)
 {
+       unsigned long flags;
+       spin_lock_irqsave(&atiixp_lock, flags);
        atiixp_set_pio_timing(ap, adev, adev->pio_mode - XFER_PIO_0);
+       spin_unlock_irqrestore(&atiixp_lock, flags);
 }
 
 /**
@@ -108,6 +113,9 @@ static void atiixp_set_dmamode(struct ata_port *ap, struct ata_device *adev)
        int dma = adev->dma_mode;
        int dn = 2 * ap->port_no + adev->devno;
        int wanted_pio;
+       unsigned long flags;
+
+       spin_lock_irqsave(&atiixp_lock, flags);
 
        if (adev->dma_mode >= XFER_UDMA_0) {
                u16 udma_mode_data;
@@ -145,6 +153,7 @@ static void atiixp_set_dmamode(struct ata_port *ap, struct ata_device *adev)
 
        if (adev->pio_mode != wanted_pio)
                atiixp_set_pio_timing(ap, adev, wanted_pio);
+       spin_unlock_irqrestore(&atiixp_lock, flags);
 }
 
 /**