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, 19 deletions

diff --git a/drivers/ide/pci/scc_pata.c b/drivers/ide/pci/scc_pata.c
index f84bf791f72e..cbf936325355 100644
--- a/drivers/ide/pci/scc_pata.c
+++ b/drivers/ide/pci/scc_pata.c
@@ -190,23 +190,6 @@ scc_ide_outsl(unsigned long port, void *addr, u32 count)
 }
 
 /**
- *      scc_ratemask    -       Compute available modes
- *      @drive: IDE drive
- *
- *      Compute the available speeds for the devices on the interface.
- *      Enforce UDMA33 as a limit if there is no 80pin cable present.
- */
-
-static u8 scc_ratemask(ide_drive_t *drive)
-{
-        u8 mode = 4;
-
-        if (!eighty_ninty_three(drive))
-                mode = min(mode, (u8)1);
-        return mode;
-}
-
-/**
  *      scc_tuneproc    -       tune a drive PIO mode
  *      @drive: drive to tune
  *      @mode_wanted: the target operating mode
@@ -273,7 +256,7 @@ static void scc_tuneproc(ide_drive_t *drive, byte mode_wanted)
 static int scc_tune_chipset(ide_drive_t *drive, byte xferspeed)
 {
         ide_hwif_t *hwif = HWIF(drive);
-        u8 speed = ide_rate_filter(scc_ratemask(drive), xferspeed);
+        u8 speed = ide_rate_filter(drive, xferspeed);
         struct scc_ports *ports = ide_get_hwifdata(hwif);
         unsigned long ctl_base = ports->ctl;
         unsigned long cckctrl_port = ctl_base + 0xff0;
@@ -347,7 +330,7 @@ static int scc_tune_chipset(ide_drive_t *drive, byte xferspeed)
 
 static int scc_config_chipset_for_dma(ide_drive_t *drive)
 {
-        u8 speed = ide_dma_speed(drive, scc_ratemask(drive));
+        u8 speed = ide_max_dma_mode(drive);
 
         if (!speed)
                 return 0;