[libata] pata_efar: add locking for parallel scanning
Add clearing of UDMA enable bit also for PIO modes and then add
extra locking for parallel scanning.
This is similar change as commit 60c3be3 for ata_piix host driver
and while pata_efar 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 kernel 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_efar.c b/drivers/ata/pata_efar.c
index 5556163..1617421 100644
--- a/drivers/ata/pata_efar.c
+++ b/drivers/ata/pata_efar.c
@@ -68,6 +68,8 @@
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 @@
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 @@
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 @@
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 @@
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 @@
{ 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 @@
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 = {
