Revert "pata_sis: Implement MWDMA for the UDMA 133 capable chips"
This reverts commit f20941f334d8fdb6b598658979709b4e94cd034b.
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: Jeff Garzik <jgarzik@redhat.com>
diff --git a/drivers/ata/pata_sis.c b/drivers/ata/pata_sis.c
index 8af0dc8..5c30d56 100644
--- a/drivers/ata/pata_sis.c
+++ b/drivers/ata/pata_sis.c
@@ -252,25 +252,24 @@
}
/**
- * 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 */
@@ -306,42 +305,6 @@
}
/**
- * 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
@@ -369,7 +332,6 @@
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 @@
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 @@
* @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 @@
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 @@
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 @@
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 ... */