1 files changed, 15 insertions, 0 deletions

diff --git a/drivers/ata/pata_efar.c b/drivers/ata/pata_efar.c
index 5556163c80de..1617421f7e76 100644
--- a/drivers/ata/pata_efar.c
+++ b/drivers/ata/pata_efar.c
@@ -68,6 +68,8 @@ static int efar_cable_detect(struct ata_port *ap)
         return ATA_CBL_PATA80;
 }
 
+static DEFINE_SPINLOCK(efar_lock);
+
 /**
  *      efar_set_piomode - Initialize host controller PATA PIO timings
  *      @ap: Port whose timings we are configuring
@@ -84,7 +86,9 @@ static void efar_set_piomode (struct ata_port *ap, struct ata_device *adev)
         unsigned int pio        = adev->pio_mode - XFER_PIO_0;
         struct pci_dev *dev     = to_pci_dev(ap->host->dev);
         unsigned int idetm_port= ap->port_no ? 0x42 : 0x40;
+        unsigned long flags;
         u16 idetm_data;
+        u8 udma_enable;
         int control = 0;
 
         /*
@@ -107,6 +111,8 @@ static void efar_set_piomode (struct ata_port *ap, struct ata_device *adev)
         if (adev->class == ATA_DEV_ATA)
                 control |= 4;   /* PPE */
 
+        spin_lock_irqsave(&efar_lock, flags);
+
         pci_read_config_word(dev, idetm_port, &idetm_data);
 
         /* Set PPE, IE, and TIME as appropriate */
@@ -131,6 +137,11 @@ static void efar_set_piomode (struct ata_port *ap, struct ata_device *adev)
 
         idetm_data |= 0x4000;   /* Ensure SITRE is set */
         pci_write_config_word(dev, idetm_port, idetm_data);
+
+        pci_read_config_byte(dev, 0x48, &udma_enable);
+        udma_enable &= ~(1 << (2 * ap->port_no + adev->devno));
+        pci_write_config_byte(dev, 0x48, udma_enable);
+        spin_unlock_irqrestore(&efar_lock, flags);
 }
 
 /**
@@ -151,6 +162,7 @@ static void efar_set_dmamode (struct ata_port *ap, struct ata_device *adev)
         u16 master_data;
         u8 speed                = adev->dma_mode;
         int devid               = adev->devno + 2 * ap->port_no;
+        unsigned long flags;
         u8 udma_enable;
 
         static const     /* ISP  RTC */
@@ -160,6 +172,8 @@ static void efar_set_dmamode (struct ata_port *ap, struct ata_device *adev)
                             { 2, 1 },
                             { 2, 3 }, };
 
+        spin_lock_irqsave(&efar_lock, flags);
+
         pci_read_config_word(dev, master_port, &master_data);
         pci_read_config_byte(dev, 0x48, &udma_enable);
 
@@ -217,6 +231,7 @@ static void efar_set_dmamode (struct ata_port *ap, struct ata_device *adev)
                 pci_write_config_word(dev, master_port, master_data);
         }
         pci_write_config_byte(dev, 0x48, udma_enable);
+        spin_unlock_irqrestore(&efar_lock, flags);
 }
 
 static struct scsi_host_template efar_sht = {