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path: root/drivers/ide/pci/piix.c
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Diffstat (limited to 'drivers/ide/pci/piix.c')
-rw-r--r--drivers/ide/pci/piix.c44
1 files changed, 11 insertions, 33 deletions
diff --git a/drivers/ide/pci/piix.c b/drivers/ide/pci/piix.c
index 38c91ba6497..4b397d64184 100644
--- a/drivers/ide/pci/piix.c
+++ b/drivers/ide/pci/piix.c
@@ -106,37 +106,6 @@
static int no_piix_dma;
/**
- * piix_dma_2_pio - return the PIO mode matching DMA
- * @xfer_rate: transfer speed
- *
- * Returns the nearest equivalent PIO timing for the DMA
- * mode requested by the controller.
- */
-
-static u8 piix_dma_2_pio (u8 xfer_rate) {
- switch(xfer_rate) {
- case XFER_UDMA_6:
- case XFER_UDMA_5:
- case XFER_UDMA_4:
- case XFER_UDMA_3:
- case XFER_UDMA_2:
- case XFER_UDMA_1:
- case XFER_UDMA_0:
- case XFER_MW_DMA_2:
- return 4;
- case XFER_MW_DMA_1:
- return 3;
- case XFER_SW_DMA_2:
- return 2;
- case XFER_MW_DMA_0:
- case XFER_SW_DMA_1:
- case XFER_SW_DMA_0:
- default:
- return 0;
- }
-}
-
-/**
* piix_set_pio_mode - set host controller for PIO mode
* @drive: drive
* @pio: PIO mode number
@@ -225,7 +194,7 @@ static void piix_set_dma_mode(ide_drive_t *drive, const u8 speed)
int u_speed = 0;
int sitre;
u16 reg4042, reg4a;
- u8 reg48, reg54, reg55;
+ u8 reg48, reg54, reg55, pio;
pci_read_config_word(dev, maslave, &reg4042);
sitre = (reg4042 & 0x4000) ? 1 : 0;
@@ -262,7 +231,11 @@ static void piix_set_dma_mode(ide_drive_t *drive, const u8 speed)
pci_write_config_byte(dev, 0x54, reg54 | v_flag);
} else
pci_write_config_byte(dev, 0x54, reg54 & ~v_flag);
+
+ pio = 4;
} else {
+ const u8 mwdma_to_pio[] = { 0, 3, 4 };
+
if (reg48 & u_flag)
pci_write_config_byte(dev, 0x48, reg48 & ~u_flag);
if (reg4a & a_speed)
@@ -271,9 +244,14 @@ static void piix_set_dma_mode(ide_drive_t *drive, const u8 speed)
pci_write_config_byte(dev, 0x54, reg54 & ~v_flag);
if (reg55 & w_flag)
pci_write_config_byte(dev, 0x55, (u8) reg55 & ~w_flag);
+
+ if (speed >= XFER_MW_DMA_0)
+ pio = mwdma_to_pio[speed - XFER_MW_DMA_0];
+ else
+ pio = 2; /* only SWDMA2 is allowed */
}
- piix_set_pio_mode(drive, piix_dma_2_pio(speed));
+ piix_set_pio_mode(drive, pio);
}
/**