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authorTejun Heo <htejun@gmail.com>2007-12-18 16:33:04 +0900
committerJeff Garzik <jeff@garzik.org>2008-01-23 05:24:12 -0500
commit5df91a25df08d85700fef5fd59bb1873273e5ef5 (patch)
treee413ff0798da2792683db0805128f43798dcfc8d /drivers/ata/libata-acpi.c
parent7c77fa4d51b1480bcec2e898c94d6912fe063c16 (diff)
libata: fix ata_acpi_gtm_xfermask()
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>
Diffstat (limited to 'drivers/ata/libata-acpi.c')
-rw-r--r--drivers/ata/libata-acpi.c42
1 files changed, 21 insertions, 21 deletions
diff --git a/drivers/ata/libata-acpi.c b/drivers/ata/libata-acpi.c
index d6697baf243d..9f0b208afcf5 100644
--- a/drivers/ata/libata-acpi.c
+++ b/drivers/ata/libata-acpi.c
@@ -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);