[PATCH] atiixp: Old drivers/ide layer driver for the ATIIXP hangfix

From: Alan
Date: Tue Jan 02 2007 - 10:48:00 EST


When the old IDE layer calls into methods in the driver during error
handling it is essentially random whether ide_lock is already held. This
causes a deadlock in the atiixp driver which also uses ide_lock internally
for locking.

Switch to a private lock instead.

Signed-off-by: Alan Cox <alan@xxxxxxxxxx>

--- linux.vanilla-2.6.20-rc3/drivers/ide/pci/atiixp.c 2007-01-01 21:43:27.000000000 +0000
+++ linux-2.6.20-rc3/drivers/ide/pci/atiixp.c 2007-01-02 15:27:37.494937880 +0000
@@ -46,6 +46,8 @@

static int save_mdma_mode[4];

+static spinlock_t atiixp_lock;
+
/**
* atiixp_ratemask - compute rate mask for ATIIXP IDE
* @drive: IDE drive to compute for
@@ -105,7 +107,7 @@
unsigned long flags;
u16 tmp16;

- spin_lock_irqsave(&ide_lock, flags);
+ spin_lock_irqsave(&atiixp_lock, flags);

pci_read_config_word(dev, ATIIXP_IDE_UDMA_CONTROL, &tmp16);
if (save_mdma_mode[drive->dn])
@@ -114,7 +116,7 @@
tmp16 |= (1 << drive->dn);
pci_write_config_word(dev, ATIIXP_IDE_UDMA_CONTROL, tmp16);

- spin_unlock_irqrestore(&ide_lock, flags);
+ spin_unlock_irqrestore(&atiixp_lock, flags);

return __ide_dma_host_on(drive);
}
@@ -125,13 +127,13 @@
unsigned long flags;
u16 tmp16;

- spin_lock_irqsave(&ide_lock, flags);
+ spin_lock_irqsave(&atiixp_lock, flags);

pci_read_config_word(dev, ATIIXP_IDE_UDMA_CONTROL, &tmp16);
tmp16 &= ~(1 << drive->dn);
pci_write_config_word(dev, ATIIXP_IDE_UDMA_CONTROL, tmp16);

- spin_unlock_irqrestore(&ide_lock, flags);
+ spin_unlock_irqrestore(&atiixp_lock, flags);

return __ide_dma_host_off(drive);
}
@@ -152,7 +154,7 @@
u32 pio_timing_data;
u16 pio_mode_data;

- spin_lock_irqsave(&ide_lock, flags);
+ spin_lock_irqsave(&atiixp_lock, flags);

pci_read_config_word(dev, ATIIXP_IDE_PIO_MODE, &pio_mode_data);
pio_mode_data &= ~(0x07 << (drive->dn * 4));
@@ -165,7 +167,7 @@
(pio_timing[pio].command_width << (timing_shift + 4));
pci_write_config_dword(dev, ATIIXP_IDE_PIO_TIMING, pio_timing_data);

- spin_unlock_irqrestore(&ide_lock, flags);
+ spin_unlock_irqrestore(&atiixp_lock, flags);
}

/**
@@ -189,7 +191,7 @@

speed = ide_rate_filter(atiixp_ratemask(drive), xferspeed);

- spin_lock_irqsave(&ide_lock, flags);
+ spin_lock_irqsave(&atiixp_lock, flags);

save_mdma_mode[drive->dn] = 0;
if (speed >= XFER_UDMA_0) {
@@ -208,7 +210,7 @@
}
}

- spin_unlock_irqrestore(&ide_lock, flags);
+ spin_unlock_irqrestore(&atiixp_lock, flags);

if (speed >= XFER_SW_DMA_0)
pio = atiixp_dma_2_pio(speed);
@@ -380,6 +382,7 @@

static int atiixp_ide_init(void)
{
+ spin_lock_init(&atiixp_lock);
return ide_pci_register_driver(&driver);
}

-
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