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, 12 deletions

diff --git a/drivers/ide/pci/sis5513.c b/drivers/ide/pci/sis5513.c
index 6fe4ecb6c06c..83c80ed73e99 100644
--- a/drivers/ide/pci/sis5513.c
+++ b/drivers/ide/pci/sis5513.c
@@ -428,16 +428,6 @@ static int sis_get_info (char *buffer, char **addr, off_t offset, int count)
 }
 #endif /* defined(DISPLAY_SIS_TIMINGS) && defined(CONFIG_PROC_FS) */
 
-static u8 sis5513_ratemask (ide_drive_t *drive)
-{
-        u8 rates[] = { 0, 0, 1, 2, 3, 3, 4, 4 };
-        u8 mode = rates[chipset_family];
-
-        if (!eighty_ninty_three(drive))
-                mode = min(mode, (u8)1);
-        return mode;
-}
-
 /*
  * Configuration functions
  */
@@ -563,7 +553,7 @@ static int sis5513_tune_chipset (ide_drive_t *drive, u8 xferspeed)
         u8 drive_pci, reg, speed;
         u32 regdw;
 
-        speed = ide_rate_filter(sis5513_ratemask(drive), xferspeed);
+        speed = ide_rate_filter(drive, xferspeed);
 
         /* See config_art_rwp_pio for drive pci config registers */
         drive_pci = 0x40;
@@ -653,7 +643,7 @@ static void sis5513_tune_drive (ide_drive_t *drive, u8 pio)
  */
 static int config_chipset_for_dma (ide_drive_t *drive)
 {
-        u8 speed        = ide_dma_speed(drive, sis5513_ratemask(drive));
+        u8 speed = ide_max_dma_mode(drive);
 
 #ifdef DEBUG
         printk("SIS5513: config_chipset_for_dma, drive %d, ultra %x\n",