diff mbox

[2/6] pata_sis: Implement MWDMA for the UDMA 133 capable chips

Message ID 20091130132248.27236.35287.stgit@localhost.localdomain
State Not Applicable
Delegated to: David Miller
Headers show

Commit Message

Alan Cox Nov. 30, 2009, 1:22 p.m. UTC 
Bartlomiej pointed out that while this got fixed in the old driver whoever
did it didn't port it across.

Signed-off-by: Alan Cox <alan@linux.intel.com>
---

 drivers/ata/pata_sis.c |   91 ++++++++++++++++++++++++++++++++++++------------
 1 files changed, 69 insertions(+), 22 deletions(-)



--
To unsubscribe from this list: send the line "unsubscribe linux-ide" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Comments

Sergei Shtylyov Dec. 7, 2009, 1:26 p.m. UTC | #1 
Hello.

Alan Cox wrote:

> Bartlomiej pointed out that while this got fixed in the old driver whoever
> did it didn't port it across.

> Signed-off-by: Alan Cox <alan@linux.intel.com>

[...]

> +static int mwdma_clip_to_pio(struct ata_device *adev)
> +{
> +	const int mwdma_to_pio[3] = {
> +		XFER_PIO_0, XFER_PIO_3, XFER_PIO_4
> +	};
> +	return min(mwdma_to_pio[adev->dma_mode - XFER_MW_DMA_0],
> +				adev->pio_mode - XFER_PIO_0);
> +}

    You call min() on uncomparables, i.e. mwdma_to_pio[] contains XFER_PIO_* 
and adev->pio_mode - XFER_PIO_0 yields you a mode number. Thus the second 
argument will always "win" as a minimal one.

MBR, Sergei
--
To unsubscribe from this list: send the line "unsubscribe linux-ide" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Bartlomiej Zolnierkiewicz Dec. 7, 2009, 3:05 p.m. UTC | #2 
On Monday 07 December 2009 02:26:00 pm Sergei Shtylyov wrote:
> Hello.
> 
> Alan Cox wrote:
> 
> > Bartlomiej pointed out that while this got fixed in the old driver whoever
> > did it didn't port it across.
> 
> > Signed-off-by: Alan Cox <alan@linux.intel.com>
> 
> [...]
> 
> > +static int mwdma_clip_to_pio(struct ata_device *adev)
> > +{
> > +	const int mwdma_to_pio[3] = {
> > +		XFER_PIO_0, XFER_PIO_3, XFER_PIO_4
> > +	};
> > +	return min(mwdma_to_pio[adev->dma_mode - XFER_MW_DMA_0],
> > +				adev->pio_mode - XFER_PIO_0);
> > +}
> 
>     You call min() on uncomparables, i.e. mwdma_to_pio[] contains XFER_PIO_* 
> and adev->pio_mode - XFER_PIO_0 yields you a mode number. Thus the second 
> argument will always "win" as a minimal one.

There are more issues with the patch related to mwdma_clip_to_pio().

The function can return values between 0 and 4 which obviously won't work
well for the new code below for values > 2 (i.e. resulting in out-of-bounds
array access for the common-case of dev->pio_mode == 4).

@@ -400,21 +439,25 @@ static void sis_100_set_dmamode (struct ata_port *ap, struct ata_device *adev)
        struct pci_dev *pdev    = to_pci_dev(ap->host->dev);
        int speed = adev->dma_mode - XFER_MW_DMA_0;
        int drive_pci = sis_old_port_base(adev);
-       u8 timing;
+       u16 timing;
 
-       const u8 udma_bits[]  = { 0x8B, 0x87, 0x85, 0x83, 0x82, 0x81};
+       const u16 udma_bits[]  = {
+               0x8B00, 0x8700, 0x8500, 0x8300, 0x8200, 0x8100};
+       const u8 mwdma_bits[] = { 0x08, 0x32, 0x31 };
 
-       pci_read_config_byte(pdev, drive_pci + 1, &timing);
+       pci_read_config_word(pdev, drive_pci, &timing);
 
        if (adev->dma_mode < XFER_UDMA_0) {
-               /* NOT SUPPORTED YET: NEED DATA SHEET. DITTO IN OLD DRIVER */
+               speed = mwdma_clip_to_pio(adev);
+               timing &= ~0x80FF;
+               timing |= mwdma_bits[speed];
        } else {
                /* Bit 7 is UDMA on/off, bit 0-3 are cycle time */
                speed = adev->dma_mode - XFER_UDMA_0;
-               timing &= ~0x8F;
+               timing &= ~0x8F00;
                timing |= udma_bits[speed];
        }
-       pci_write_config_byte(pdev, drive_pci + 1, timing);
+       pci_write_config_word(pdev, drive_pci, timing);
 }
 
 /**
@@ -434,21 +477,26 @@ static void sis_133_early_set_dmamode (struct ata_port *ap, struct ata_device *a
        struct pci_dev *pdev    = to_pci_dev(ap->host->dev);
        int speed = adev->dma_mode - XFER_MW_DMA_0;
        int drive_pci = sis_old_port_base(adev);
-       u8 timing;
-       /* Low 4 bits are timing */
-       static const u8 udma_bits[]  = { 0x8F, 0x8A, 0x87, 0x85, 0x83, 0x82, 0x81};
+       u16 timing;
+       /* Bits 15-12  are timing */
+       static const u16 udma_bits[]  = {
+               0x8F00, 0x8A00, 0x8700, 0x8500, 0x8300, 0x8200, 0x8100
+       };
+       static const u8 mwdma_bits[] = { 0x08, 0x32, 0x31 };
 
-       pci_read_config_byte(pdev, drive_pci + 1, &timing);
+       pci_read_config_word(pdev, drive_pci, &timing);
 
        if (adev->dma_mode < XFER_UDMA_0) {
-               /* NOT SUPPORTED YET: NEED DATA SHEET. DITTO IN OLD DRIVER */
+               speed = mwdma_clip_to_pio(adev);
+               timing &= ~0x80FF;
+               timing = mwdma_bits[speed];
        } else {
                /* Bit 7 is UDMA on/off, bit 0-3 are cycle time */
                speed = adev->dma_mode - XFER_UDMA_0;
-               timing &= ~0x8F;
+               timing &= ~0x8F00;
                timing |= udma_bits[speed];
        }
-       pci_write_config_byte(pdev, drive_pci + 1, timing);
+       pci_write_config_word(pdev, drive_pci, timing);
 }
 
 /**


--
Bartlomiej Zolnierkiewicz
--
To unsubscribe from this list: send the line "unsubscribe linux-ide" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Bartlomiej Zolnierkiewicz Dec. 7, 2009, 3:11 p.m. UTC | #3 
On Monday 07 December 2009 04:05:28 pm Bartlomiej Zolnierkiewicz wrote:

> array access for the common-case of dev->pio_mode == 4).

s/4/XFER_PIO_4/

[ Looking at the buggy code is bad for your health. ]
--
To unsubscribe from this list: send the line "unsubscribe linux-ide" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Bartlomiej Zolnierkiewicz Dec. 7, 2009, 3:36 p.m. UTC | #4 
On Monday 07 December 2009 04:05:28 pm Bartlomiej Zolnierkiewicz wrote:
> On Monday 07 December 2009 02:26:00 pm Sergei Shtylyov wrote:
> > Hello.
> > 
> > Alan Cox wrote:
> > 
> > > Bartlomiej pointed out that while this got fixed in the old driver whoever
> > > did it didn't port it across.
> > 
> > > Signed-off-by: Alan Cox <alan@linux.intel.com>
> > 
> > [...]
> > 
> > > +static int mwdma_clip_to_pio(struct ata_device *adev)
> > > +{
> > > +	const int mwdma_to_pio[3] = {
> > > +		XFER_PIO_0, XFER_PIO_3, XFER_PIO_4
> > > +	};
> > > +	return min(mwdma_to_pio[adev->dma_mode - XFER_MW_DMA_0],
> > > +				adev->pio_mode - XFER_PIO_0);
> > > +}
> > 
> >     You call min() on uncomparables, i.e. mwdma_to_pio[] contains XFER_PIO_* 
> > and adev->pio_mode - XFER_PIO_0 yields you a mode number. Thus the second 
> > argument will always "win" as a minimal one.
> 
> There are more issues with the patch related to mwdma_clip_to_pio().
> 
> The function can return values between 0 and 4 which obviously won't work
> well for the new code below for values > 2 (i.e. resulting in out-of-bounds

Fortunately above bugs won't be triggered because the patch forgot to update
MWDMA masks..  ;)

What is even more interesting is that the driver currently also lacks support
for MWDMA modes on UDMA66 chips (though it was implemented in the driver).

static const struct ata_port_info sis_info66 = {
	.flags		= ATA_FLAG_SLAVE_POSS,
	.pio_mask	= ATA_PIO4,
	/* No MWDMA */
	.udma_mask	= ATA_UDMA4,
	.port_ops	= &sis_66_ops,
};
static const struct ata_port_info sis_info100 = {
	.flags		= ATA_FLAG_SLAVE_POSS,
	.pio_mask	= ATA_PIO4,
	/* No MWDMA */
	.udma_mask	= ATA_UDMA5,
	.port_ops	= &sis_100_ops,
};
static const struct ata_port_info sis_info100_early = {
	.flags		= ATA_FLAG_SLAVE_POSS,
	.pio_mask	= ATA_PIO4,
	/* No MWDMA */
	.udma_mask	= ATA_UDMA5,
	.port_ops	= &sis_66_ops,
};
static const struct ata_port_info sis_info133 = {
	.flags		= ATA_FLAG_SLAVE_POSS,
	.pio_mask	= ATA_PIO4,
	/* No MWDMA */
	.udma_mask	= ATA_UDMA6,
	.port_ops	= &sis_133_ops,
};
const struct ata_port_info sis_info133_for_sata = {
	.flags		= ATA_FLAG_SLAVE_POSS | ATA_FLAG_SRST,
	.pio_mask	= ATA_PIO4,
	/* No MWDMA */
	.udma_mask	= ATA_UDMA6,
	.port_ops	= &sis_133_for_sata_ops,
};
static const struct ata_port_info sis_info133_early = {
	.flags		= ATA_FLAG_SLAVE_POSS,
	.pio_mask	= ATA_PIO4,
	/* No MWDMA */
	.udma_mask	= ATA_UDMA6,
	.port_ops	= &sis_133_early_ops,
};

--
Bartlomiej Zolnierkiewicz
--
To unsubscribe from this list: send the line "unsubscribe linux-ide" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Bartlomiej Zolnierkiewicz Dec. 7, 2009, 3:53 p.m. UTC | #5 
On Monday 07 December 2009 04:36:31 pm Bartlomiej Zolnierkiewicz wrote:
> On Monday 07 December 2009 04:05:28 pm Bartlomiej Zolnierkiewicz wrote:
> > On Monday 07 December 2009 02:26:00 pm Sergei Shtylyov wrote:
> > > Hello.
> > > 
> > > Alan Cox wrote:
> > > 
> > > > Bartlomiej pointed out that while this got fixed in the old driver whoever
> > > > did it didn't port it across.
> > > 
> > > > Signed-off-by: Alan Cox <alan@linux.intel.com>
> > > 
> > > [...]

One more thing:

@@ -479,13 +527,12 @@ static void sis_133_set_dmamode (struct ata_port *ap, struct ata_device *adev)
 	if (reg54 & 0x40000000)
 		port = 0x70;
 	port += (8 * ap->port_no) +  (4 * adev->devno);
-
 	pci_read_config_dword(pdev, port, &t1);
 
 	if (adev->dma_mode < XFER_UDMA_0) {
-		t1 &= ~0x00000004;
-		/* FIXME: need data sheet to add MWDMA here. Also lacking on
-		   ide/pci driver */
+		speed = mwdma_clip_to_pio(adev);
+		sis_133_do_piomode(ap, adev, speed);
+		t1 &= ~4;	/* UDMA off */
 	} else {
 		speed = adev->dma_mode - XFER_UDMA_0;
 		/* if & 8 no UDMA133 - need info for ... */

This way of doing things results in under-clocked timings for MWDMA0 mode,
(they're not the same as ones for PIO0 mode), old driver gets it correctly.

--
Bartlomiej Zolnierkiewicz
--
To unsubscribe from this list: send the line "unsubscribe linux-ide" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Bartlomiej Zolnierkiewicz Dec. 7, 2009, 4:34 p.m. UTC | #6 
On Monday 07 December 2009 04:05:28 pm Bartlomiej Zolnierkiewicz wrote:
> On Monday 07 December 2009 02:26:00 pm Sergei Shtylyov wrote:
> > Hello.
> > 
> > Alan Cox wrote:
> > 
> > > Bartlomiej pointed out that while this got fixed in the old driver whoever
> > > did it didn't port it across.
> > 
> > > Signed-off-by: Alan Cox <alan@linux.intel.com>
> > 
> > [...]
> > 
> > > +static int mwdma_clip_to_pio(struct ata_device *adev)
> > > +{
> > > +	const int mwdma_to_pio[3] = {
> > > +		XFER_PIO_0, XFER_PIO_3, XFER_PIO_4
> > > +	};
> > > +	return min(mwdma_to_pio[adev->dma_mode - XFER_MW_DMA_0],
> > > +				adev->pio_mode - XFER_PIO_0);
> > > +}
> > 
> >     You call min() on uncomparables, i.e. mwdma_to_pio[] contains XFER_PIO_* 
> > and adev->pio_mode - XFER_PIO_0 yields you a mode number. Thus the second 
> > argument will always "win" as a minimal one.
> 
> There are more issues with the patch related to mwdma_clip_to_pio().

Hmm.. why cannot ->qc_issue be used here (like in all other host drivers with
shared PIO/MWDMA timings) instead of some new 'clipping'?

->qc_issue is the standard way to do it, takes care of more corner cases
and would also allow for faster MWDMA0 timings. 

--
Bartlomiej Zolnierkiewicz
--
To unsubscribe from this list: send the line "unsubscribe linux-ide" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Alan Cox Dec. 7, 2009, 5:53 p.m. UTC | #7 
> Hmm.. why cannot ->qc_issue be used here (like in all other host drivers with
> shared PIO/MWDMA timings) instead of some new 'clipping'?

Agreed it would probably work providing the 8bit timings are not affected
by any of this.

> ->qc_issue is the standard way to do it, takes care of more corner cases
> and would also allow for faster MWDMA0 timings. 

All yours.. just revert the buggy patch and fix it. I won't have time to
look at it until next year and I freecycled all my SiS hardware some time
ago.

Alan
--
To unsubscribe from this list: send the line "unsubscribe linux-ide" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Bartlomiej Zolnierkiewicz Dec. 7, 2009, 6:36 p.m. UTC | #8 
On Monday 07 December 2009 06:53:14 pm Alan Cox wrote:
> > Hmm.. why cannot ->qc_issue be used here (like in all other host drivers with
> > shared PIO/MWDMA timings) instead of some new 'clipping'?
> 
> Agreed it would probably work providing the 8bit timings are not affected
> by any of this.

If 8bit timings are a problem ->bmdma_{start,stop} approach can be used
instead (as done for similar reason in it821x IIRC).

> > ->qc_issue is the standard way to do it, takes care of more corner cases
> > and would also allow for faster MWDMA0 timings. 
> 
> All yours.. just revert the buggy patch and fix it. I won't have time to
> look at it until next year and I freecycled all my SiS hardware some time
> ago.

Thank you but this is quite a bit of work and I'm not interested personally.

--
Bartlomiej Zolnierkiewicz
--
To unsubscribe from this list: send the line "unsubscribe linux-ide" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
diff mbox

Patch

diff --git a/drivers/ata/pata_sis.c b/drivers/ata/pata_sis.c
index 488e77b..d70ecec 100644
--- a/drivers/ata/pata_sis.c
+++ b/drivers/ata/pata_sis.c
@@ -252,24 +252,25 @@  static void sis_100_set_piomode (struct ata_port *ap, struct ata_device *adev)
 }
 
 /**
- *	sis_133_set_piomode - Initialize host controller PATA PIO timings
+ *	sis_133_do_piomode - Initialize host controller PATA PIO/DMA timings
  *	@ap: Port whose timings we are configuring
  *	@adev: Device we are configuring for.
  *
  *	Set PIO mode for device, in host controller PCI config space. This
- *	function handles PIO set up for the later ATA133 devices.
+ *	function handles PIO set up for the later ATA133 devices. The same
+ *	timings are used for MWDMA.
  *
  *	LOCKING:
  *	None (inherited from caller).
  */
 
-static void sis_133_set_piomode (struct ata_port *ap, struct ata_device *adev)
+static void sis_133_do_piomode(struct ata_port *ap, struct ata_device *adev,
+					int speed)
 {
 	struct pci_dev *pdev	= to_pci_dev(ap->host->dev);
 	int port = 0x40;
 	u32 t1;
 	u32 reg54;
-	int speed = adev->pio_mode - XFER_PIO_0;
 
 	const u32 timing133[] = {
 		0x28269000,	/* Recovery << 24 | Act << 16 | Ini << 12 */
@@ -305,6 +306,42 @@  static void sis_133_set_piomode (struct ata_port *ap, struct ata_device *adev)
 }
 
 /**
+ *	sis_133_set_piomode - Initialize host controller PATA PIO timings
+ *	@ap: Port whose timings we are configuring
+ *	@adev: Device we are configuring for.
+ *
+ *	Set PIO mode for device, in host controller PCI config space. This
+ *	function handles PIO set up for the later ATA133 devices.
+ *
+ *	LOCKING:
+ *	None (inherited from caller).
+ */
+
+static void sis_133_set_piomode (struct ata_port *ap, struct ata_device *adev)
+{
+
+	sis_133_do_piomode(ap, adev, adev->pio_mode - XFER_PIO_0);
+}
+
+/**
+ *	mwdma_clip_to_pio		-	clip MWDMA mode
+ *	@adev: device
+ *
+ *	As the SiS shared MWDMA and PIO timings we must program the equivalent
+ *	PIO timing for the MWDMA mode but we must not program one higher than
+ *	the permitted PIO timing of the device.
+ */
+
+static int mwdma_clip_to_pio(struct ata_device *adev)
+{
+	const int mwdma_to_pio[3] = {
+		XFER_PIO_0, XFER_PIO_3, XFER_PIO_4
+	};
+	return min(mwdma_to_pio[adev->dma_mode - XFER_MW_DMA_0],
+				adev->pio_mode - XFER_PIO_0);
+}
+
+/**
  *	sis_old_set_dmamode - Initialize host controller PATA DMA timings
  *	@ap: Port whose timings we are configuring
  *	@adev: Device to program
@@ -332,6 +369,7 @@  static void sis_old_set_dmamode (struct ata_port *ap, struct ata_device *adev)
 	if (adev->dma_mode < XFER_UDMA_0) {
 		/* bits 3-0 hold recovery timing bits 8-10 active timing and
 		   the higher bits are dependant on the device */
+		speed = mwdma_clip_to_pio(adev);
 		timing &= ~0x870F;
 		timing |= mwdma_bits[speed];
 	} else {
@@ -372,6 +410,7 @@  static void sis_66_set_dmamode (struct ata_port *ap, struct ata_device *adev)
 	if (adev->dma_mode < XFER_UDMA_0) {
 		/* bits 3-0 hold recovery timing bits 8-10 active timing and
 		   the higher bits are dependant on the device, bit 15 udma */
+		speed = mwdma_clip_to_pio(adev);
 		timing &= ~0x870F;
 		timing |= mwdma_bits[speed];
 	} else {
@@ -389,7 +428,7 @@  static void sis_66_set_dmamode (struct ata_port *ap, struct ata_device *adev)
  *	@adev: Device to program
  *
  *	Set UDMA/MWDMA mode for device, in host controller PCI config space.
- *	Handles UDMA66 and early UDMA100 devices.
+ *	Handles later UDMA100 devices.
  *
  *	LOCKING:
  *	None (inherited from caller).
@@ -400,21 +439,25 @@  static void sis_100_set_dmamode (struct ata_port *ap, struct ata_device *adev)
 	struct pci_dev *pdev	= to_pci_dev(ap->host->dev);
 	int speed = adev->dma_mode - XFER_MW_DMA_0;
 	int drive_pci = sis_old_port_base(adev);
-	u8 timing;
+	u16 timing;
 
-	const u8 udma_bits[]  = { 0x8B, 0x87, 0x85, 0x83, 0x82, 0x81};
+	const u16 udma_bits[]  = {
+		0x8B00, 0x8700, 0x8500, 0x8300, 0x8200, 0x8100};
+	const u8 mwdma_bits[] = { 0x08, 0x32, 0x31 };
 
-	pci_read_config_byte(pdev, drive_pci + 1, &timing);
+	pci_read_config_word(pdev, drive_pci, &timing);
 
 	if (adev->dma_mode < XFER_UDMA_0) {
-		/* NOT SUPPORTED YET: NEED DATA SHEET. DITTO IN OLD DRIVER */
+		speed = mwdma_clip_to_pio(adev);
+		timing &= ~0x80FF;
+		timing |= mwdma_bits[speed];
 	} else {
 		/* Bit 7 is UDMA on/off, bit 0-3 are cycle time */
 		speed = adev->dma_mode - XFER_UDMA_0;
-		timing &= ~0x8F;
+		timing &= ~0x8F00;
 		timing |= udma_bits[speed];
 	}
-	pci_write_config_byte(pdev, drive_pci + 1, timing);
+	pci_write_config_word(pdev, drive_pci, timing);
 }
 
 /**
@@ -434,21 +477,26 @@  static void sis_133_early_set_dmamode (struct ata_port *ap, struct ata_device *a
 	struct pci_dev *pdev	= to_pci_dev(ap->host->dev);
 	int speed = adev->dma_mode - XFER_MW_DMA_0;
 	int drive_pci = sis_old_port_base(adev);
-	u8 timing;
-	/* Low 4 bits are timing */
-	static const u8 udma_bits[]  = { 0x8F, 0x8A, 0x87, 0x85, 0x83, 0x82, 0x81};
+	u16 timing;
+	/* Bits 15-12  are timing */
+	static const u16 udma_bits[]  = {
+		0x8F00, 0x8A00, 0x8700, 0x8500, 0x8300, 0x8200, 0x8100
+	};
+	static const u8 mwdma_bits[] = { 0x08, 0x32, 0x31 };
 
-	pci_read_config_byte(pdev, drive_pci + 1, &timing);
+	pci_read_config_word(pdev, drive_pci, &timing);
 
 	if (adev->dma_mode < XFER_UDMA_0) {
-		/* NOT SUPPORTED YET: NEED DATA SHEET. DITTO IN OLD DRIVER */
+		speed = mwdma_clip_to_pio(adev);
+		timing &= ~0x80FF;
+		timing = mwdma_bits[speed];
 	} else {
 		/* Bit 7 is UDMA on/off, bit 0-3 are cycle time */
 		speed = adev->dma_mode - XFER_UDMA_0;
-		timing &= ~0x8F;
+		timing &= ~0x8F00;
 		timing |= udma_bits[speed];
 	}
-	pci_write_config_byte(pdev, drive_pci + 1, timing);
+	pci_write_config_word(pdev, drive_pci, timing);
 }
 
 /**
@@ -479,13 +527,12 @@  static void sis_133_set_dmamode (struct ata_port *ap, struct ata_device *adev)
 	if (reg54 & 0x40000000)
 		port = 0x70;
 	port += (8 * ap->port_no) +  (4 * adev->devno);
-
 	pci_read_config_dword(pdev, port, &t1);
 
 	if (adev->dma_mode < XFER_UDMA_0) {
-		t1 &= ~0x00000004;
-		/* FIXME: need data sheet to add MWDMA here. Also lacking on
-		   ide/pci driver */
+		speed = mwdma_clip_to_pio(adev);
+		sis_133_do_piomode(ap, adev, speed);
+		t1 &= ~4;	/* UDMA off */
 	} else {
 		speed = adev->dma_mode - XFER_UDMA_0;
 		/* if & 8 no UDMA133 - need info for ... */