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libata: fix ata_acpi_gtm_xfermask()

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ata_acpi_gtm_xfermask() as separated out from pacpi_discover_modes()
has various bugs.  Fix them.

* The wrong comparison operator is used when finding for matching
  cycle resulting totally bogus result.

* With the comparion operator fixed, boundary condtion handling is
  clumsy.

* Setting of any DMA mask bit set all bits in PIO mask.

* MWDMA and UDMA blocks are swapped.

Signed-off-by: Tejun Heo <htejun@gmail.com>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
This commit is contained in:
Tejun Heo 2007-12-18 16:33:04 +09:00 committed by Jeff Garzik
parent 7c77fa4d51
commit 5df91a25df
1 changed files with 21 additions and 21 deletions
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42
drivers/ata/libata-acpi.c
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@ -473,49 +473,49 @@ EXPORT_SYMBOL_GPL(ata_acpi_udma_cycle);
unsigned long ata_acpi_gtm_xfermask(struct ata_device *dev,
const struct ata_acpi_gtm *gtm)
{
unsigned long pio_mask = 0, mwdma_mask = 0, udma_mask = 0;
int unit, i;
u32 t;
unsigned long mask = (0x7f << ATA_SHIFT_UDMA) | (0x7 << ATA_SHIFT_MWDMA) | (0x1F << ATA_SHIFT_PIO);
/* we always use the 0 slot for crap hardware */
unit = dev->devno;
if (!(gtm->flags & 0x10))
unit = 0;
/* Values larger than the longest cycle results in 0 mask
* while values equal to smaller than the shortest cycle
* results in mask which includes all supported modes.
* Disabled transfer method has the value of 0xffffffff which
* will always result in 0 mask.
*/
/* start by scanning for PIO modes */
for (i = 0; i < 7; i++) {
t = gtm->drive[unit].pio;
if (t <= ata_acpi_pio_cycle[i]) {
mask |= (2 << (ATA_SHIFT_PIO + i)) - 1;
t = gtm->drive[unit].pio;
for (i = 0; i < ARRAY_SIZE(ata_acpi_pio_cycle); i++)
if (t > ata_acpi_pio_cycle[i])
break;
}
}
pio_mask = (1 << i) - 1;
/* See if we have MWDMA or UDMA data. We don't bother with
* MWDMA if UDMA is available as this means the BIOS set UDMA
* and our error changedown if it works is UDMA to PIO anyway.
*/
if (gtm->flags & (1 << (2 * unit))) {
t = gtm->drive[unit].dma;
if (!(gtm->flags & (1 << (2 * unit)))) {
/* MWDMA */
for (i = 0; i < 5; i++) {
t = gtm->drive[unit].dma;
if (t <= ata_acpi_mwdma_cycle[i]) {
mask |= (2 << (ATA_SHIFT_MWDMA + i)) - 1;
for (i = 0; i < ARRAY_SIZE(ata_acpi_mwdma_cycle); i++)
if (t > ata_acpi_mwdma_cycle[i])
break;
}
}
mwdma_mask = (1 << i) - 1;
} else {
/* UDMA */
for (i = 0; i < 7; i++) {
t = gtm->drive[unit].dma;
if (t <= ata_acpi_udma_cycle[i]) {
mask |= (2 << (ATA_SHIFT_UDMA + i)) - 1;
for (i = 0; i < ARRAY_SIZE(ata_acpi_udma_cycle); i++)
if (t > ata_acpi_udma_cycle[i])
break;
}
}
udma_mask = (1 << i) - 1;
}
return mask;
return ata_pack_xfermask(pio_mask, mwdma_mask, udma_mask);
}
EXPORT_SYMBOL_GPL(ata_acpi_gtm_xfermask);