ide: rework the code for selecting the best DMA transfer mode (v3)

Depends on the "ide: fix UDMA/MWDMA/SWDMA masks" patch.

* add ide_hwif_t.udma_filter hook for filtering UDMA mask
  (use it in alim15x3, hpt366, siimage and serverworks drivers)
* add ide_max_dma_mode() for finding best DMA mode for the device
  (loosely based on some older libata-core.c code)
* convert ide_dma_speed() users to use ide_max_dma_mode()
* make ide_rate_filter() take "ide_drive_t *drive" as an argument instead
  of "u8 mode" and teach it to how to use UDMA mask to do filtering
* use ide_rate_filter() in hpt366 driver
* remove no longer needed ide_dma_speed() and *_ratemask()
* unexport eighty_ninty_three()

v2:
* rename ->filter_udma_mask to ->udma_filter
  [ Suggested by Sergei Shtylyov <sshtylyov@ru.mvista.com>. ]

v3:
* updated for scc_pata driver (fixes XFER_UDMA_6 filtering for user-space
  originated transfer mode change requests when 100MHz clock is used)

Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>

1 files changed, 2 insertions, 7 deletions

diff --git a/drivers/ide/pci/tc86c001.c b/drivers/ide/pci/tc86c001.c
index 0b6d81d6ce48..168f035caa3f 100644
--- a/drivers/ide/pci/tc86c001.c
+++ b/drivers/ide/pci/tc86c001.c
@@ -13,18 +13,13 @@
 #include <linux/pci.h>
 #include <linux/ide.h>
 
-static inline u8 tc86c001_ratemask(ide_drive_t *drive)
-{
-        return eighty_ninty_three(drive) ? 2 : 1;
-}
-
 static int tc86c001_tune_chipset(ide_drive_t *drive, u8 speed)
 {
         ide_hwif_t *hwif        = HWIF(drive);
         unsigned long scr_port  = hwif->config_data + (drive->dn ? 0x02 : 0x00);
         u16 mode, scr           = hwif->INW(scr_port);
 
-        speed = ide_rate_filter(tc86c001_ratemask(drive), speed);
+        speed = ide_rate_filter(drive, speed);
 
         switch (speed) {
                 case XFER_UDMA_4:       mode = 0x00c0; break;
@@ -174,7 +169,7 @@ static int tc86c001_busproc(ide_drive_t *drive, int state)
 
 static int config_chipset_for_dma(ide_drive_t *drive)
 {
-        u8 speed = ide_dma_speed(drive, tc86c001_ratemask(drive));
+        u8 speed = ide_max_dma_mode(drive);
 
         if (!speed)
                 return 0;