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@xxxxxxxxxxxxxxx>
>
> [...]
>
> > +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@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
