[PATCH] 2.5.20 IDE 84

 - Simplify ide_cmd_type_parse by removing the handling of commands which we
   never use.

 - Realize that pre_task_out_intr and pre_task_mulout_intr are semanticaly
   identical. Use only pre_task_out_intr(). This allowed us to
   eliminate the prehandler altogether.

 - Updated fix for misconfigured host chips by Vojtech Pavlik.

 - Be more permissive about ioctl handling to allow device type drivers to do
   they own checks.

 - ali14xx cleanups by Andrej Panin.

 - Unfold usage ide_cmd_type_parser in tcq.c code. This makes this operation
   local to ide-disk.c. Move it as well as the interrupt handlers used only for
   the handling of disk requests there too.

 - Guard against calling handler before the drive is ready for it in
   ata_taskfile()! Well this bug was there before, but right now we inform
   about it.

 - Unfold ide_cmd_type_praser in ide-disk.c. Merge the remaining bits of it with
   get_command. Well it's no more.

 - Move recal_intr to ide.c - the only place where it's used.

This doesn't change the "mechanics" of the code but it makes it a lot more
"obvious" what's going on.

arch/i386/pci/fixup.c

@@ -99,17 +99,6 @@ static void __devinit  pci_fixup_ide_trash(struct pci_dev *d)
 		d->resource[i].start = d->resource[i].end = d->resource[i].flags = 0;
 }
 
-static void __devinit pci_fixup_ide_exbar(struct pci_dev *d)
-{
-	/*
-	 * Some new Intel IDE controllers have an EXBAR register for
-	 * MMIO instead of PIO. It's unused, undocumented (though maybe
-	 * functional). BIOSes often assign conflicting memory address
-	 * to this. Just kill it.
-	 */
-	d->resource[5].start = d->resource[5].end = d->resource[5].flags = 0;
-}
-
 static void __devinit  pci_fixup_latency(struct pci_dev *d)
 {
 	/*
@@ -185,9 +174,9 @@ struct pci_fixup pcibios_fixups[] = {
 	{ PCI_FIXUP_HEADER,	PCI_VENDOR_ID_SI,	PCI_DEVICE_ID_SI_5597,		pci_fixup_latency },
 	{ PCI_FIXUP_HEADER,	PCI_VENDOR_ID_SI,	PCI_DEVICE_ID_SI_5598,		pci_fixup_latency },
  	{ PCI_FIXUP_HEADER,	PCI_VENDOR_ID_INTEL,	PCI_DEVICE_ID_INTEL_82371AB_3,	pci_fixup_piix4_acpi },
- 	{ PCI_FIXUP_HEADER,	PCI_VENDOR_ID_INTEL,	PCI_DEVICE_ID_INTEL_82801CA_10,	pci_fixup_ide_exbar },
- 	{ PCI_FIXUP_HEADER,	PCI_VENDOR_ID_INTEL,	PCI_DEVICE_ID_INTEL_82801CA_11,	pci_fixup_ide_exbar },
- 	{ PCI_FIXUP_HEADER,	PCI_VENDOR_ID_INTEL,	PCI_DEVICE_ID_INTEL_82801DB_9,	pci_fixup_ide_exbar },
+ 	{ PCI_FIXUP_HEADER,	PCI_VENDOR_ID_INTEL,	PCI_DEVICE_ID_INTEL_82801CA_10,	pci_fixup_ide_trash },
+ 	{ PCI_FIXUP_HEADER,	PCI_VENDOR_ID_INTEL,	PCI_DEVICE_ID_INTEL_82801CA_11,	pci_fixup_ide_trash },
+ 	{ PCI_FIXUP_HEADER,	PCI_VENDOR_ID_INTEL,	PCI_DEVICE_ID_INTEL_82801DB_9,	pci_fixup_ide_trash },
 	{ PCI_FIXUP_HEADER,	PCI_VENDOR_ID_VIA,	PCI_DEVICE_ID_VIA_8363_0,	pci_fixup_via_northbridge_bug },
 	{ PCI_FIXUP_HEADER,	PCI_VENDOR_ID_VIA,	PCI_DEVICE_ID_VIA_8622,	        pci_fixup_via_northbridge_bug },
 	{ PCI_FIXUP_HEADER,	PCI_VENDOR_ID_VIA,	PCI_DEVICE_ID_VIA_8361,	        pci_fixup_via_northbridge_bug },

drivers/ide/ali14xx.c

@@ -13,7 +13,7 @@
  * I think the code should be pretty understandable,
  * but I'll be happy to (try to) answer questions.
  *
- * The critical part is in the setupDrive function.  The initRegisters
+ * The critical part is in the ali14xx_tune_drive function.  The init_registers
  * function doesn't seem to be necessary, but the DOS driver does it, so
  * I threw it in.
  *
@@ -37,12 +37,6 @@
 
 #include <linux/types.h>
 #include <linux/kernel.h>
-#include <linux/delay.h>
-#include <linux/timer.h>
-#include <linux/mm.h>
-#include <linux/ioport.h>
-#include <linux/blkdev.h>
-#include <linux/hdreg.h>
 #include <linux/ide.h>
 #include <linux/init.h>
 
@@ -52,12 +46,14 @@
 
 /* port addresses for auto-detection */
 #define ALI_NUM_PORTS 4
-static int ports[ALI_NUM_PORTS] __initdata = {0x074, 0x0f4, 0x034, 0x0e4};
+static int ports[ALI_NUM_PORTS] __initdata = { 0x074, 0x0f4, 0x034, 0x0e4 };
 
 /* register initialization data */
-typedef struct { byte reg, data; } RegInitializer;
+struct reg_initializer {
+	u8 reg, data; 
+};
 
-static RegInitializer initData[] __initdata = {
+static struct reg_initializer init_data[] __initdata = {
 	{0x01, 0x0f}, {0x02, 0x00}, {0x03, 0x00}, {0x04, 0x00},
 	{0x05, 0x00}, {0x06, 0x00}, {0x07, 0x2b}, {0x0a, 0x0f},
 	{0x25, 0x00}, {0x26, 0x00}, {0x27, 0x00}, {0x28, 0x00},
@@ -68,37 +64,37 @@ static RegInitializer initData[] __initdata = {
 };
 
 /* timing parameter registers for each drive */
-static struct { byte reg1, reg2, reg3, reg4; } regTab[4] = {
-	{0x03, 0x26, 0x04, 0x27},     /* drive 0 */
-	{0x05, 0x28, 0x06, 0x29},     /* drive 1 */
-	{0x2b, 0x30, 0x2c, 0x31},     /* drive 2 */
-	{0x2d, 0x32, 0x2e, 0x33},     /* drive 3 */
+static struct {
+	u8 reg1, reg2, reg3, reg4;
+} reg_tab[4] = {
+	{ 0x03, 0x26, 0x04, 0x27 },	/* drive 0 */
+	{ 0x05, 0x28, 0x06, 0x29 },	/* drive 1 */
+	{ 0x2b, 0x30, 0x2c, 0x31 },	/* drive 2 */
+	{ 0x2d, 0x32, 0x2e, 0x33 },	/* drive 3 */
 };
 
-static int basePort;	/* base port address */
-static int regPort;	/* port for register number */
-static int dataPort;	/* port for register data */
-static byte regOn;	/* output to base port to access registers */
-static byte regOff;	/* output to base port to close registers */
-
-/*------------------------------------------------------------------------*/
+static int base_port;	/* base port address */
+static int reg_port;	/* port for register number */
+static int data_port;	/* port for register data */
+static u8 reg_on;	/* output to base port to access registers */
+static u8 reg_off;	/* output to base port to close registers */
 
 /*
  * Read a controller register.
  */
-static inline byte inReg (byte reg)
+static inline u8 in_reg(u8 reg)
 {
-	outb_p(reg, regPort);
-	return inb(dataPort);
+	outb_p(reg, reg_port);
+	return inb(data_port);
 }
 
 /*
  * Write a controller register.
  */
-static void outReg (byte data, byte reg)
+static inline void out_reg(u8 data, u8 reg)
 {
-	outb_p(reg, regPort);
-	outb_p(data, dataPort);
+	outb_p(reg, reg_port);
+	outb_p(data, data_port);
 }
 
 /*
@@ -108,7 +104,7 @@ static void outReg (byte data, byte reg)
  */
 static void ali14xx_tune_drive(struct ata_device *drive, u8 pio)
 {
-	int driveNum;
+	int drive_num;
 	int time1, time2;
 	u8 param1, param2, param3, param4;
 	unsigned long flags;
@@ -117,7 +113,7 @@ static void ali14xx_tune_drive(struct ata_device *drive, u8 pio)
 	if (pio == 255)
 		pio = ata_timing_mode(drive, XFER_PIO | XFER_EPIO);
 	else
-		pio = XFER_PIO_0 + min_t(byte, pio, 4);
+		pio = XFER_PIO_0 + min_t(u8, pio, 4);
 
 	t = ata_timing_data(pio);
 
@@ -130,50 +126,50 @@ static void ali14xx_tune_drive(struct ata_device *drive, u8 pio)
 		param3 += 8;
 		param4 += 8;
 	}
-	printk("%s: PIO mode%d, t1=%dns, t2=%dns, cycles = %d+%d, %d+%d\n",
+	printk(KERN_DEBUG "%s: PIO mode%d, t1=%dns, t2=%dns, cycles = %d+%d, %d+%d\n",
 		drive->name, pio - XFER_PIO_0, time1, time2, param1, param2, param3, param4);
 
 	/* stuff timing parameters into controller registers */
-	driveNum = (drive->channel->index << 1) + drive->select.b.unit;
+	drive_num = (drive->channel->index << 1) + drive->select.b.unit;
 	save_flags(flags);	/* all CPUs */
 	cli();			/* all CPUs */
-	outb_p(regOn, basePort);
-	outReg(param1, regTab[driveNum].reg1);
-	outReg(param2, regTab[driveNum].reg2);
-	outReg(param3, regTab[driveNum].reg3);
-	outReg(param4, regTab[driveNum].reg4);
-	outb_p(regOff, basePort);
+	outb_p(reg_on, base_port);
+	out_reg(param1, reg_tab[drive_num].reg1);
+	out_reg(param2, reg_tab[drive_num].reg2);
+	out_reg(param3, reg_tab[drive_num].reg3);
+	out_reg(param4, reg_tab[drive_num].reg4);
+	outb_p(reg_off, base_port);
 	restore_flags(flags);	/* all CPUs */
 }
 
 /*
  * Auto-detect the IDE controller port.
  */
-static int __init findPort (void)
+static int __init find_port(void)
 {
 	int i;
-	byte t;
 	unsigned long flags;
 
 	__save_flags(flags);	/* local CPU only */
 	__cli();		/* local CPU only */
-	for (i = 0; i < ALI_NUM_PORTS; ++i) {
-		basePort = ports[i];
-		regOff = inb(basePort);
-		for (regOn = 0x30; regOn <= 0x33; ++regOn) {
-			outb_p(regOn, basePort);
-			if (inb(basePort) == regOn) {
-				regPort = basePort + 4;
-				dataPort = basePort + 8;
-				t = inReg(0) & 0xf0;
-				outb_p(regOff, basePort);
+	for (i = 0; i < ALI_NUM_PORTS; i++) {
+		base_port = ports[i];
+		reg_off = inb(base_port);
+		for (reg_on = 0x30; reg_on <= 0x33; reg_on++) {
+			outb_p(reg_on, base_port);
+			if (inb(base_port) == reg_on) {
+				u8 t;
+				reg_port = base_port + 4;
+				data_port = base_port + 8;
+				t = in_reg(0) & 0xf0;
+				outb_p(reg_off, base_port);
 				__restore_flags(flags);	/* local CPU only */
 				if (t != 0x50)
 					return 0;
-				return 1;  /* success */
+				return 1;	/* success */
 			}
 		}
-		outb_p(regOff, basePort);
+		outb_p(reg_off, base_port);
 	}
 	__restore_flags(flags);	/* local CPU only */
 	return 0;
@@ -182,32 +178,34 @@ static int __init findPort (void)
 /*
  * Initialize controller registers with default values.
  */
-static int __init initRegisters (void) {
-	RegInitializer *p;
-	byte t;
+static int __init init_registers(void)
+{
+	struct reg_initializer *p;
 	unsigned long flags;
+	u8 t;
 
 	__save_flags(flags);	/* local CPU only */
 	__cli();		/* local CPU only */
-	outb_p(regOn, basePort);
-	for (p = initData; p->reg != 0; ++p)
-		outReg(p->data, p->reg);
-	outb_p(0x01, regPort);
-	t = inb(regPort) & 0x01;
-	outb_p(regOff, basePort);
+	outb_p(reg_on, base_port);
+	for (p = init_data; p->reg != 0; ++p)
+		out_reg(p->data, p->reg);
+	outb_p(0x01, reg_port);
+	t = inb(reg_port) & 0x01;
+	outb_p(reg_off, base_port);
 	__restore_flags(flags);	/* local CPU only */
 	return t;
 }
 
-void __init init_ali14xx (void)
+void __init init_ali14xx(void)
 {
 	/* auto-detect IDE controller port */
-	if (!findPort()) {
-		printk("\nali14xx: not found");
+	if (!find_port()) {
+		printk(KERN_ERR "ali14xx: not found\n");
 		return;
 	}
 
-	printk("\nali14xx: base= 0x%03x, regOn = 0x%02x", basePort, regOn);
+	printk(KERN_DEBUG "ali14xx: base=%#03x, reg_on=%#02x\n",
+		base_port, reg_on);
 	ide_hwifs[0].chipset = ide_ali14xx;
 	ide_hwifs[1].chipset = ide_ali14xx;
 	ide_hwifs[0].tuneproc = &ali14xx_tune_drive;
@@ -216,8 +214,8 @@ void __init init_ali14xx (void)
 	ide_hwifs[1].unit = ATA_SECONDARY;
 
 	/* initialize controller registers */
-	if (!initRegisters()) {
-		printk("\nali14xx: Chip initialization failed");
+	if (!init_registers()) {
+		printk(KERN_ERR "ali14xx: Chip initialization failed\n");
 		return;
 	}
 }

drivers/ide/ide.c

@@ -67,9 +67,6 @@
 #include "pcihost.h"
 #include "ioctl.h"
 
-/* default maximum number of failures */
-#define IDE_DEFAULT_MAX_FAILURES	1
-
 /*
  * CompactFlash cards and their relatives pretend to be removable hard disks, except:
  *	(1) they never have a slave unit, and
@@ -554,6 +551,19 @@ static void try_to_flush_leftover_data(struct ata_device *drive)
 # define IS_PDC4030_DRIVE (0)	/* auto-NULLs out pdc4030 code */
 #endif
 
+/*
+ * This is invoked on completion of a WIN_RESTORE (recalibrate) cmd.
+ *
+ * FIXME: Why can't be just use task_no_data_intr here?
+ */
+static ide_startstop_t recal_intr(struct ata_device *drive, struct request *rq)
+{
+	if (!ata_status(drive, READY_STAT, BAD_STAT))
+		return ata_error(drive, rq, __FUNCTION__);
+
+	return ide_stopped;
+}
+
 /*
  * We are still on the old request path here so issuing the recalibrate command
  * directly should just work.
@@ -572,6 +582,7 @@ static int do_recalibrate(struct ata_device *drive)
 		args.taskfile.sector_count = drive->sect;
 		args.cmd = WIN_RESTORE;
 		args.handler = recal_intr;
+		args.command_type = IDE_DRIVE_TASK_NO_DATA;
 		ata_taskfile(drive, &args, NULL);
 	}
 

drivers/ide/ioctl.c

@@ -150,19 +150,22 @@ int ata_ioctl(struct inode *inode, struct file *file, unsigned int cmd, unsigned
 	 * configuration.
 	 */
 
-	if (!capable(CAP_SYS_ADMIN))
-		return -EACCES;
-
 	switch (cmd) {
 		case HDIO_GET_32BIT: {
 			unsigned long val = drive->channel->io_32bit;
 
+			if (!capable(CAP_SYS_ADMIN))
+				return -EACCES;
+
 			if (put_user(val, (unsigned long *) arg))
 				return -EFAULT;
 			return 0;
 		}
 
 		case HDIO_SET_32BIT:
+		        if (!capable(CAP_SYS_ADMIN))
+				return -EACCES;
+
 			if (arg < 0 || arg > 1)
 				return -EINVAL;
 
@@ -178,6 +181,9 @@ int ata_ioctl(struct inode *inode, struct file *file, unsigned int cmd, unsigned
 			return 0;
 
 		case HDIO_SET_PIO_MODE:
+			if (!capable(CAP_SYS_ADMIN))
+				return -EACCES;
+
 			if (arg < 0 || arg > 255)
 				return -EINVAL;
 
@@ -198,6 +204,9 @@ int ata_ioctl(struct inode *inode, struct file *file, unsigned int cmd, unsigned
 		case HDIO_GET_UNMASKINTR: {
 			unsigned long val = drive->channel->unmask;
 
+			if (!capable(CAP_SYS_ADMIN))
+				return -EACCES;
+
 			if (put_user(val, (unsigned long *) arg))
 				return -EFAULT;
 
@@ -205,6 +214,9 @@ int ata_ioctl(struct inode *inode, struct file *file, unsigned int cmd, unsigned
 		}
 
 		case HDIO_SET_UNMASKINTR:
+			if (!capable(CAP_SYS_ADMIN))
+				return -EACCES;
+
 			if (arg < 0 || arg > 1)
 				return -EINVAL;
 
@@ -222,6 +234,9 @@ int ata_ioctl(struct inode *inode, struct file *file, unsigned int cmd, unsigned
 		case HDIO_GET_DMA: {
 			unsigned long val = drive->using_dma;
 
+			if (!capable(CAP_SYS_ADMIN))
+				return -EACCES;
+
 			if (put_user(val, (unsigned long *) arg))
 				return -EFAULT;
 
@@ -229,6 +244,9 @@ int ata_ioctl(struct inode *inode, struct file *file, unsigned int cmd, unsigned
 		}
 
 		case HDIO_SET_DMA:
+			if (!capable(CAP_SYS_ADMIN))
+				return -EACCES;
+
 			if (arg < 0 || arg > 1)
 				return -EINVAL;
 
@@ -250,6 +268,9 @@ int ata_ioctl(struct inode *inode, struct file *file, unsigned int cmd, unsigned
 			struct hd_geometry *loc = (struct hd_geometry *) arg;
 			unsigned short bios_cyl = drive->bios_cyl; /* truncate */
 
+			if (!capable(CAP_SYS_ADMIN))
+				return -EACCES;
+
 			if (!loc || (drive->type != ATA_DISK && drive->type != ATA_FLOPPY))
 				return -EINVAL;
 
@@ -272,6 +293,9 @@ int ata_ioctl(struct inode *inode, struct file *file, unsigned int cmd, unsigned
 		case HDIO_GETGEO_BIG_RAW: {
 			struct hd_big_geometry *loc = (struct hd_big_geometry *) arg;
 
+			if (!capable(CAP_SYS_ADMIN))
+				return -EACCES;
+
 			if (!loc || (drive->type != ATA_DISK && drive->type != ATA_FLOPPY))
 				return -EINVAL;
 
@@ -292,6 +316,9 @@ int ata_ioctl(struct inode *inode, struct file *file, unsigned int cmd, unsigned
 		}
 
 		case HDIO_GET_IDENTITY:
+			if (!capable(CAP_SYS_ADMIN))
+				return -EACCES;
+
 			if (minor(inode->i_rdev) & PARTN_MASK)
 				return -EINVAL;
 
@@ -304,11 +331,17 @@ int ata_ioctl(struct inode *inode, struct file *file, unsigned int cmd, unsigned
 			return 0;
 
 		case HDIO_GET_NICE:
+			if (!capable(CAP_SYS_ADMIN))
+				return -EACCES;
+
 			return put_user(drive->dsc_overlap << IDE_NICE_DSC_OVERLAP |
 					drive->atapi_overlap << IDE_NICE_ATAPI_OVERLAP,
 					(long *) arg);
 
 		case HDIO_SET_NICE:
+			if (!capable(CAP_SYS_ADMIN))
+				return -EACCES;
+
 			if (arg != (arg & ((1 << IDE_NICE_DSC_OVERLAP))))
 				return -EPERM;
 
@@ -322,18 +355,27 @@ int ata_ioctl(struct inode *inode, struct file *file, unsigned int cmd, unsigned
 			return 0;
 
 		case HDIO_GET_BUSSTATE:
+			if (!capable(CAP_SYS_ADMIN))
+				return -EACCES;
+
 			if (put_user(drive->channel->bus_state, (long *)arg))
 				return -EFAULT;
 
 			return 0;
 
 		case HDIO_SET_BUSSTATE:
+			if (!capable(CAP_SYS_ADMIN))
+				return -EACCES;
+
 			if (drive->channel->busproc)
 				drive->channel->busproc(drive, (int)arg);
 
 			return 0;
 
 		case HDIO_DRIVE_CMD:
+			if (!capable(CAP_SYS_ADMIN))
+				return -EACCES;
+
 			if (!arg) {
 				if (ide_spin_wait_hwgroup(drive))
 					return -EBUSY;

drivers/ide/tcq.c

@@ -406,7 +406,8 @@ static int check_autopoll(struct ata_device *drive)
 
 	args.taskfile.feature = 0x01;
 	args.cmd = WIN_NOP;
-	ide_cmd_type_parser(&args);
+	args.handler = task_no_data_intr;
+	args.command_type = IDE_DRIVE_TASK_NO_DATA;
 
 	/*
 	 * do taskfile and check ABRT bit -- intelligent adapters will not
@@ -441,7 +442,8 @@ static int configure_tcq(struct ata_device *drive)
 	memset(&args, 0, sizeof(args));
 	args.taskfile.feature = SETFEATURES_EN_WCACHE;
 	args.cmd = WIN_SETFEATURES;
-	ide_cmd_type_parser(&args);
+	args.handler = task_no_data_intr;
+	args.command_type = IDE_DRIVE_TASK_NO_DATA;
 
 	if (ide_raw_taskfile(drive, &args)) {
 		printk("%s: failed to enable write cache\n", drive->name);
@@ -455,7 +457,8 @@ static int configure_tcq(struct ata_device *drive)
 	memset(&args, 0, sizeof(args));
 	args.taskfile.feature = SETFEATURES_DIS_RI;
 	args.cmd = WIN_SETFEATURES;
-	ide_cmd_type_parser(&args);
+	args.handler = task_no_data_intr;
+	args.command_type = IDE_DRIVE_TASK_NO_DATA;
 
 	if (ide_raw_taskfile(drive, &args)) {
 		printk("%s: disabling release interrupt fail\n", drive->name);
@@ -469,7 +472,8 @@ static int configure_tcq(struct ata_device *drive)
 	memset(&args, 0, sizeof(args));
 	args.taskfile.feature = SETFEATURES_EN_SI;
 	args.cmd = WIN_SETFEATURES;
-	ide_cmd_type_parser(&args);
+	args.handler = task_no_data_intr;
+	args.command_type = IDE_DRIVE_TASK_NO_DATA;
 
 	if (ide_raw_taskfile(drive, &args)) {
 		printk("%s: enabling service interrupt fail\n", drive->name);

include/linux/ide.h

@@ -664,7 +664,6 @@ struct ata_taskfile {
 	struct hd_drive_task_hdr  hobfile;
 	u8 cmd;					/* actual ATA command */
 	int command_type;
-	ide_startstop_t (*prehandler)(struct ata_device *, struct request *);
 	ide_startstop_t (*handler)(struct ata_device *, struct request *);
 };
 
@@ -678,17 +677,31 @@ extern ide_startstop_t ata_taskfile(struct ata_device *,
  * Special Flagged Register Validation Caller
  */
 
-extern ide_startstop_t recal_intr(struct ata_device *, struct request *);
-extern ide_startstop_t task_no_data_intr(struct ata_device *, struct request *);
+/*
+ * for now, taskfile requests are special :/
+ */
+static inline char *ide_map_rq(struct request *rq, unsigned long *flags)
+{
+	if (rq->bio)
+		return bio_kmap_irq(rq->bio, flags) + ide_rq_offset(rq);
+	else
+		return rq->buffer + ((rq)->nr_sectors - (rq)->current_nr_sectors) * SECTOR_SIZE;
+}
 
-extern void ide_cmd_type_parser(struct ata_taskfile *args);
+static inline void ide_unmap_rq(struct request *rq, char *to,
+				unsigned long *flags)
+{
+	if (rq->bio)
+		bio_kunmap_irq(to, flags);
+}
+
+extern ide_startstop_t task_no_data_intr(struct ata_device *, struct request *);
 extern int ide_raw_taskfile(struct ata_device *, struct ata_taskfile *);
 
 extern void ide_fix_driveid(struct hd_driveid *id);
 extern int ide_config_drive_speed(struct ata_device *, byte);
 extern byte eighty_ninty_three(struct ata_device *);
 
-
 extern void ide_stall_queue(struct ata_device *, unsigned long);
 
 extern int system_bus_speed;