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, 25 deletions

diff --git a/drivers/ide/pci/pdc202xx_old.c b/drivers/ide/pci/pdc202xx_old.c
index d7a38067fb34..207a6191fac7 100644
--- a/drivers/ide/pci/pdc202xx_old.c
+++ b/drivers/ide/pci/pdc202xx_old.c
@@ -101,35 +101,12 @@ static const char *pdc_quirk_drives[] = {
 #define MC1             0x02    /* DMA"C" timing */
 #define MC0             0x01    /* DMA"C" timing */
 
-static u8 pdc202xx_ratemask (ide_drive_t *drive)
-{
-        u8 mode;
-
-        switch(HWIF(drive)->pci_dev->device) {
-                case PCI_DEVICE_ID_PROMISE_20267:
-                case PCI_DEVICE_ID_PROMISE_20265:
-                        mode = 3;
-                        break;
-                case PCI_DEVICE_ID_PROMISE_20263:
-                case PCI_DEVICE_ID_PROMISE_20262:
-                        mode = 2;
-                        break;
-                case PCI_DEVICE_ID_PROMISE_20246:
-                        return 1;
-                default:
-                        return 0;
-        }
-        if (!eighty_ninty_three(drive))
-                mode = min(mode, (u8)1);
-        return mode;
-}
-
 static int pdc202xx_tune_chipset (ide_drive_t *drive, u8 xferspeed)
 {
         ide_hwif_t *hwif        = HWIF(drive);
         struct pci_dev *dev     = hwif->pci_dev;
         u8 drive_pci            = 0x60 + (drive->dn << 2);
-        u8 speed        = ide_rate_filter(pdc202xx_ratemask(drive), xferspeed);
+        u8 speed                = ide_rate_filter(drive, xferspeed);
 
         u32                     drive_conf;
         u8                      AP, BP, CP, DP;
@@ -308,7 +285,7 @@ chipset_is_set:
         if (drive->media == ide_disk)   /* PREFETCH_EN */
                 pci_write_config_byte(dev, (drive_pci), AP|PREFETCH_EN);
 
-        speed = ide_dma_speed(drive, pdc202xx_ratemask(drive));
+        speed = ide_max_dma_mode(drive);
 
         if (!(speed)) {
                 /* restore original pci-config space */