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, 18 deletions

diff --git a/drivers/ide/pci/atiixp.c b/drivers/ide/pci/atiixp.c
index 2d48af32e3f4..f7e80d6076d7 100644
--- a/drivers/ide/pci/atiixp.c
+++ b/drivers/ide/pci/atiixp.c
@@ -49,22 +49,6 @@ static int save_mdma_mode[4];
 static DEFINE_SPINLOCK(atiixp_lock);
 
 /**
- *      atiixp_ratemask         -       compute rate mask for ATIIXP IDE
- *      @drive: IDE drive to compute for
- *
- *      Returns the available modes for the ATIIXP IDE controller.
- */
-
-static u8 atiixp_ratemask(ide_drive_t *drive)
-{
-        u8 mode = 3;
-
-        if (!eighty_ninty_three(drive))
-                mode = min(mode, (u8)1);
-        return mode;
-}
-
-/**
  *      atiixp_dma_2_pio                -       return the PIO mode matching DMA
  *      @xfer_rate: transfer speed
  *
@@ -189,7 +173,7 @@ static int atiixp_speedproc(ide_drive_t *drive, u8 xferspeed)
         u16 tmp16;
         u8 speed, pio;
 
-        speed = ide_rate_filter(atiixp_ratemask(drive), xferspeed);
+        speed = ide_rate_filter(drive, xferspeed);
 
         spin_lock_irqsave(&atiixp_lock, flags);
 
@@ -233,7 +217,7 @@ static int atiixp_speedproc(ide_drive_t *drive, u8 xferspeed)
 
 static int atiixp_config_drive_for_dma(ide_drive_t *drive)
 {
-        u8 speed = ide_dma_speed(drive, atiixp_ratemask(drive));
+        u8 speed = ide_max_dma_mode(drive);
 
         if (!speed)
                 return 0;