ide-pmac: remove pmac_ide_do_setfeature() (take 2)

Use ide_config_drive_speed() instead of pmac_ide_do_setfeature() and remove
the latter, also  ide-iops.c::__ide_wait_stat() could be static again.

Since for IDE PMAC host driver IDE_CONTROL_REG is always true, device's
->quirk_list is always zero and ->ide_dma_host_{on,off} are nops than
the only changes in behavior are:

* if PIO mode is set then ->dma_off_queitly is called to disable DMA

* if setting transfer mode fails ide_dump_status() is called to dump status

v2:
* IDE PMAC controllers allow separate PIO and DMA timings and PPC userland
  depends on this fact, and calls "hdparm -p" without calling "hdparm -d".

  Therefore to compensate for DMA being disabled by ide_config_drive_speed()
  for PIO modes:

  - add IDE_HFLAG_SET_PIO_MODE_KEEP_DMA flag and set it in PMAC host driver

  - add handling of the new flag to ide-io.c::do_special()

Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>

1 files changed, 9 insertions, 1 deletions

diff --git a/drivers/ide/ide-io.c b/drivers/ide/ide-io.c
index 9560a8f4a86c..4cece930114c 100644
--- a/drivers/ide/ide-io.c
+++ b/drivers/ide/ide-io.c
@@ -836,9 +836,17 @@ static ide_startstop_t do_special (ide_drive_t *drive)
                 if (set_pio_mode_abuse(drive->hwif, req_pio)) {
                         if (hwif->set_pio_mode)
                                 hwif->set_pio_mode(drive, req_pio);
-                } else
+                } else {
+                        int keep_dma = drive->using_dma;
+
                         ide_set_pio(drive, req_pio);
 
+                        if (hwif->host_flags & IDE_HFLAG_SET_PIO_MODE_KEEP_DMA) {
+                                if (keep_dma)
+                                        hwif->ide_dma_on(drive);
+                        }
+                }
+
                 return ide_stopped;
         } else {
                 if (drive->media == ide_disk)