1 files changed, 8 insertions, 0 deletions

diff --git a/drivers/ata/ata_piix.c b/drivers/ata/ata_piix.c
index 7409f98d2ae6..3971bc0a4838 100644
--- a/drivers/ata/ata_piix.c
+++ b/drivers/ata/ata_piix.c
@@ -158,6 +158,7 @@ struct piix_map_db {
 struct piix_host_priv {
         const int *map;
         u32 saved_iocfg;
+        spinlock_t sidpr_lock;  /* FIXME: remove once locking in EH is fixed */
         void __iomem *sidpr;
 };
 
@@ -951,12 +952,15 @@ static int piix_sidpr_scr_read(struct ata_link *link,
                                unsigned int reg, u32 *val)
 {
         struct piix_host_priv *hpriv = link->ap->host->private_data;
+        unsigned long flags;
 
         if (reg >= ARRAY_SIZE(piix_sidx_map))
                 return -EINVAL;
 
+        spin_lock_irqsave(&hpriv->sidpr_lock, flags);
         piix_sidpr_sel(link, reg);
         *val = ioread32(hpriv->sidpr + PIIX_SIDPR_DATA);
+        spin_unlock_irqrestore(&hpriv->sidpr_lock, flags);
         return 0;
 }
 
@@ -964,12 +968,15 @@ static int piix_sidpr_scr_write(struct ata_link *link,
                                 unsigned int reg, u32 val)
 {
         struct piix_host_priv *hpriv = link->ap->host->private_data;
+        unsigned long flags;
 
         if (reg >= ARRAY_SIZE(piix_sidx_map))
                 return -EINVAL;
 
+        spin_lock_irqsave(&hpriv->sidpr_lock, flags);
         piix_sidpr_sel(link, reg);
         iowrite32(val, hpriv->sidpr + PIIX_SIDPR_DATA);
+        spin_unlock_irqrestore(&hpriv->sidpr_lock, flags);
         return 0;
 }
 
@@ -1566,6 +1573,7 @@ static int __devinit piix_init_one(struct pci_dev *pdev,
         hpriv = devm_kzalloc(dev, sizeof(*hpriv), GFP_KERNEL);
         if (!hpriv)
                 return -ENOMEM;
+        spin_lock_init(&hpriv->sidpr_lock);
 
         /* Save IOCFG, this will be used for cable detection, quirk
          * detection and restoration on detach.  This is necessary