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path: root/drivers/ide/ide-dma.c
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Diffstat (limited to 'drivers/ide/ide-dma.c')
-rw-r--r--drivers/ide/ide-dma.c48
1 files changed, 32 insertions, 16 deletions
diff --git a/drivers/ide/ide-dma.c b/drivers/ide/ide-dma.c
index ff644a5..6000c08 100644
--- a/drivers/ide/ide-dma.c
+++ b/drivers/ide/ide-dma.c
@@ -653,7 +653,7 @@ static const u8 xfer_mode_bases[] = {
XFER_SW_DMA_0,
};
-static unsigned int ide_get_mode_mask(ide_drive_t *drive, u8 base)
+static unsigned int ide_get_mode_mask(ide_drive_t *drive, u8 base, u8 req_mode)
{
struct hd_driveid *id = drive->id;
ide_hwif_t *hwif = drive->hwif;
@@ -664,17 +664,28 @@ static unsigned int ide_get_mode_mask(ide_drive_t *drive, u8 base)
if ((id->field_valid & 4) == 0)
break;
- mask = id->dma_ultra & hwif->ultra_mask;
-
if (hwif->udma_filter)
- mask &= hwif->udma_filter(drive);
+ mask = hwif->udma_filter(drive);
+ else
+ mask = hwif->ultra_mask;
+ mask &= id->dma_ultra;
- if ((mask & 0x78) && (eighty_ninty_three(drive) == 0))
- mask &= 0x07;
+ /*
+ * avoid false cable warning from eighty_ninty_three()
+ */
+ if (req_mode > XFER_UDMA_2) {
+ if ((mask & 0x78) && (eighty_ninty_three(drive) == 0))
+ mask &= 0x07;
+ }
break;
case XFER_MW_DMA_0:
- if (id->field_valid & 2)
- mask = id->dma_mword & hwif->mwdma_mask;
+ if ((id->field_valid & 2) == 0)
+ break;
+ if (hwif->mdma_filter)
+ mask = hwif->mdma_filter(drive);
+ else
+ mask = hwif->mwdma_mask;
+ mask &= id->dma_mword;
break;
case XFER_SW_DMA_0:
if (id->field_valid & 2) {
@@ -703,15 +714,18 @@ static unsigned int ide_get_mode_mask(ide_drive_t *drive, u8 base)
}
/**
- * ide_max_dma_mode - compute DMA speed
+ * ide_find_dma_mode - compute DMA speed
* @drive: IDE device
+ * @req_mode: requested mode
+ *
+ * Checks the drive/host capabilities and finds the speed to use for
+ * the DMA transfer. The speed is then limited by the requested mode.
*
- * Checks the drive capabilities and returns the speed to use
- * for the DMA transfer. Returns 0 if the drive is incapable
- * of DMA transfers.
+ * Returns 0 if the drive/host combination is incapable of DMA transfers
+ * or if the requested mode is not a DMA mode.
*/
-u8 ide_max_dma_mode(ide_drive_t *drive)
+u8 ide_find_dma_mode(ide_drive_t *drive, u8 req_mode)
{
ide_hwif_t *hwif = drive->hwif;
unsigned int mask;
@@ -722,7 +736,9 @@ u8 ide_max_dma_mode(ide_drive_t *drive)
return 0;
for (i = 0; i < ARRAY_SIZE(xfer_mode_bases); i++) {
- mask = ide_get_mode_mask(drive, xfer_mode_bases[i]);
+ if (req_mode < xfer_mode_bases[i])
+ continue;
+ mask = ide_get_mode_mask(drive, xfer_mode_bases[i], req_mode);
x = fls(mask) - 1;
if (x >= 0) {
mode = xfer_mode_bases[i] + x;
@@ -732,10 +748,10 @@ u8 ide_max_dma_mode(ide_drive_t *drive)
printk(KERN_DEBUG "%s: selected mode 0x%x\n", drive->name, mode);
- return mode;
+ return min(mode, req_mode);
}
-EXPORT_SYMBOL_GPL(ide_max_dma_mode);
+EXPORT_SYMBOL_GPL(ide_find_dma_mode);
int ide_tune_dma(ide_drive_t *drive)
{