ide: use only ->set_pio_mode method for programming PIO modes (take 2)

Use ->set_pio_mode method to program PIO modes in ide_set_xfer_rate()
(the only place which used ->speedproc to program PIO modes) and remove
handling of PIO modes from all ->speedproc implementations.

v2:
* Fix pmac_ide_tune_chipset() comment.

There should be no functionality changes caused by this patch.

Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
diff --git a/drivers/ide/ide-lib.c b/drivers/ide/ide-lib.c
index 8400b1b..d97390c 100644
--- a/drivers/ide/ide-lib.c
+++ b/drivers/ide/ide-lib.c
@@ -398,6 +398,18 @@
 
 	rate = ide_rate_filter(drive, rate);
 
+	if (rate >= XFER_PIO_0 && rate <= XFER_PIO_5) {
+		if (hwif->set_pio_mode)
+			hwif->set_pio_mode(drive, rate - XFER_PIO_0);
+
+		/*
+		 * FIXME: this is incorrect to return zero here but
+		 * since all users of ide_set_xfer_rate() ignore
+		 * the return value it is not a problem currently
+		 */
+		return 0;
+	}
+
 	return hwif->speedproc(drive, rate);
 }