Commit 1b52f2a4 authored by Jeff Garzik's avatar Jeff Garzik Committed by Jeff Garzik
Browse files

Revert "pata_sis: Implement MWDMA for the UDMA 133 capable chips" 



This reverts commit f20941f3.

Sergei Shtylyov notes "You call min() on uncomparables [in
mwdma_clip_to_pio()], 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"

Bartlomiej Zolnierkiewicz adds "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 == XFER_PIO_4)."

Bartlomiej Zolnierkiewicz also notes the patch is incomplete, failing to
update MWDMA mode masks.

Signed-off-by: default avatarJeff Garzik <jgarzik@redhat.com>
parent d0634c4a

drivers/ata/pata_sis.c

+22 −69
Original line number Diff line number Diff line
@@ -252,25 +252,24 @@ static void sis_100_set_piomode (struct ata_port *ap, struct ata_device *adev) 
}



/**

 *	sis_133_do_piomode - Initialize host controller PATA PIO/DMA timings

 *	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. The same

 *	timings are used for MWDMA.

 *	function handles PIO set up for the later ATA133 devices.

 *

 *	LOCKING:

 *	None (inherited from caller).

 */



static void sis_133_do_piomode(struct ata_port *ap, struct ata_device *adev,

					int speed)

static void sis_133_set_piomode (struct ata_port *ap, struct ata_device *adev)

{

	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 */
@@ -305,42 +304,6 @@ static void sis_133_do_piomode(struct ata_port *ap, struct ata_device *adev, 
	pci_write_config_byte(pdev, port, t1);

}



/**

 *	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
@@ -369,7 +332,6 @@ 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 {
@@ -410,7 +372,6 @@ 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 {
@@ -428,7 +389,7 @@ 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 later UDMA100 devices.

 *	Handles UDMA66 and early UDMA100 devices.

 *

 *	LOCKING:

 *	None (inherited from caller).
@@ -439,25 +400,21 @@ 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);

	u16 timing;

	u8 timing;



	const u16 udma_bits[]  = {

		0x8B00, 0x8700, 0x8500, 0x8300, 0x8200, 0x8100};

	const u8 mwdma_bits[] = { 0x08, 0x32, 0x31 };

	const u8 udma_bits[]  = { 0x8B, 0x87, 0x85, 0x83, 0x82, 0x81};



	pci_read_config_word(pdev, drive_pci, &timing);

	pci_read_config_byte(pdev, drive_pci + 1, &timing);



	if (adev->dma_mode < XFER_UDMA_0) {

		speed = mwdma_clip_to_pio(adev);

		timing &= ~0x80FF;

		timing |= mwdma_bits[speed];

		/* NOT SUPPORTED YET: NEED DATA SHEET. DITTO IN OLD DRIVER */

	} else {

		/* Bit 7 is UDMA on/off, bit 0-3 are cycle time */

		speed = adev->dma_mode - XFER_UDMA_0;

		timing &= ~0x8F00;

		timing &= ~0x8F;

		timing |= udma_bits[speed];

	}

	pci_write_config_word(pdev, drive_pci, timing);

	pci_write_config_byte(pdev, drive_pci + 1, timing);

}



/**
@@ -477,26 +434,21 @@ 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);

	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 };

	u8 timing;

	/* Low 4 bits are timing */

	static const u8 udma_bits[]  = { 0x8F, 0x8A, 0x87, 0x85, 0x83, 0x82, 0x81};



	pci_read_config_word(pdev, drive_pci, &timing);

	pci_read_config_byte(pdev, drive_pci + 1, &timing);



	if (adev->dma_mode < XFER_UDMA_0) {

		speed = mwdma_clip_to_pio(adev);

		timing &= ~0x80FF;

		timing = mwdma_bits[speed];

		/* NOT SUPPORTED YET: NEED DATA SHEET. DITTO IN OLD DRIVER */

	} else {

		/* Bit 7 is UDMA on/off, bit 0-3 are cycle time */

		speed = adev->dma_mode - XFER_UDMA_0;

		timing &= ~0x8F00;

		timing &= ~0x8F;

		timing |= udma_bits[speed];

	}

	pci_write_config_word(pdev, drive_pci, timing);

	pci_write_config_byte(pdev, drive_pci + 1, timing);

}



/**
@@ -527,12 +479,13 @@ 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) {

		speed = mwdma_clip_to_pio(adev);

		sis_133_do_piomode(ap, adev, speed);

		t1 &= ~4;	/* UDMA off */

		t1 &= ~0x00000004;

		/* FIXME: need data sheet to add MWDMA here. Also lacking on

		   ide/pci driver */

	} else {

		speed = adev->dma_mode - XFER_UDMA_0;

		/* if & 8 no UDMA133 - need info for ... */

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