ide: add IDE_HFLAG_ABUSE_SET_DMA_MODE host flag

* Add IDE_HFLAG_ABUSE_SET_DMA_MODE host flag and use it to decide
  what to do with transfer modes < XFER_PIO_0 in ide_set_xfer_rate().

* Set IDE_HFLAG_ABUSE_SET_DMA_MODE in host drivers that need it
  (aec62xx, amd74xx, cs5520, cs5535, hpt34x, hpt366, pdc202xx_old,
  serverworks, tc86c001 and via82cxxx) and cleanup ->set_dma_mode
  methods in host drivers that don't (IDE core code guarantees that
  ->set_dma_mode will be called only for modes which are present
  in SWDMA/MWDMA/UDMA masks).

While at it:

* Add IDE_HFLAGS_HPT34X/HPT3XX/PDC202XX/SVWKS define in
  hpt34x/hpt366/pdc202xx_old/serverworks host driver.

There should be no functionality changes caused by this patch.

Acked-by: Sergei Shtylyov <sshtylyov@ru.mvista.com>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>

1 files changed, 16 insertions, 24 deletions

diff --git a/drivers/ide/pci/sl82c105.c b/drivers/ide/pci/sl82c105.c
index 147d783f752..069f104fdce 100644
--- a/drivers/ide/pci/sl82c105.c
+++ b/drivers/ide/pci/sl82c105.c
@@ -115,32 +115,24 @@ static void sl82c105_set_dma_mode(ide_drive_t *drive, const u8 speed)
         DBG(("sl82c105_tune_chipset(drive:%s, speed:%s)\n",
              drive->name, ide_xfer_verbose(speed)));
 
-        switch (speed) {
-        case XFER_MW_DMA_2:
-        case XFER_MW_DMA_1:
-        case XFER_MW_DMA_0:
-                drv_ctrl = mwdma_timings[speed - XFER_MW_DMA_0];
+        drv_ctrl = mwdma_timings[speed - XFER_MW_DMA_0];
 
-                /*
-                 * Store the DMA timings so that we can actually program
-                 * them when DMA will be turned on...
-                 */
-                drive->drive_data &= 0x0000ffff;
-                drive->drive_data |= (unsigned long)drv_ctrl << 16;
+        /*
+         * Store the DMA timings so that we can actually program
+         * them when DMA will be turned on...
+         */
+        drive->drive_data &= 0x0000ffff;
+        drive->drive_data |= (unsigned long)drv_ctrl << 16;
 
-                /*
-                 * If we are already using DMA, we just reprogram
-                 * the drive control register.
-                 */
-                if (drive->using_dma) {
-                        struct pci_dev *dev     = HWIF(drive)->pci_dev;
-                        int reg                 = 0x44 + drive->dn * 4;
-
-                        pci_write_config_word(dev, reg, drv_ctrl);
-                }
-                break;
-        default:
-                return;
+        /*
+         * If we are already using DMA, we just reprogram
+         * the drive control register.
+         */
+        if (drive->using_dma) {
+                struct pci_dev *dev     = HWIF(drive)->pci_dev;
+                int reg                 = 0x44 + drive->dn * 4;
+
+                pci_write_config_word(dev, reg, drv_ctrl);
         }
 }