cs5530/sc1200: add ->udma_filter methods
CS5530/SC1200 specifies that two drives on the same cable cannot mix
UDMA/MDMA. Add {cs5530,sc1200}_udma_filter() to handle this. This also
makes it possible to remove open-coded best DMA mode selection and use
standard ide_use_dma()/ide_max_dma_mode() helpers. While at it bump
version numbers.
There should be no functionality changes caused by this patch.
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
diff --git a/drivers/ide/pci/sc1200.c b/drivers/ide/pci/sc1200.c
index b5ae0c5..c0254b5 100644
--- a/drivers/ide/pci/sc1200.c
+++ b/drivers/ide/pci/sc1200.c
@@ -1,7 +1,9 @@
/*
- * linux/drivers/ide/pci/sc1200.c Version 0.91 28-Jan-2003
+ * linux/drivers/ide/pci/sc1200.c Version 0.92 Mar 10 2007
*
* Copyright (C) 2000-2002 Mark Lord <mlord@pobox.com>
+ * Copyright (C) 2007 Bartlomiej Zolnierkiewicz
+ *
* May be copied or modified under the terms of the GNU General Public License
*
* Development of this chipset driver was funded
@@ -93,57 +95,33 @@
*/
//#define SC1200_BAD_PIO(timings) (((timings)&~0x80000000)==0x00009172)
-static int sc1200_autoselect_dma_mode (ide_drive_t *drive)
+/*
+ * The SC1200 specifies that two drives sharing a cable cannot mix
+ * UDMA/MDMA. It has to be one or the other, for the pair, though
+ * different timings can still be chosen for each drive. We could
+ * set the appropriate timing bits on the fly, but that might be
+ * a bit confusing. So, for now we statically handle this requirement
+ * by looking at our mate drive to see what it is capable of, before
+ * choosing a mode for our own drive.
+ */
+static u8 sc1200_udma_filter(ide_drive_t *drive)
{
- int udma_ok = 1, mode = 0;
- ide_hwif_t *hwif = HWIF(drive);
- int unit = drive->select.b.unit;
- ide_drive_t *mate = &hwif->drives[unit^1];
- struct hd_driveid *id = drive->id;
+ ide_hwif_t *hwif = drive->hwif;
+ ide_drive_t *mate = &hwif->drives[(drive->dn & 1) ^ 1];
+ struct hd_driveid *mateid = mate->id;
+ u8 mask = hwif->ultra_mask;
- /*
- * The SC1200 specifies that two drives sharing a cable cannot
- * mix UDMA/MDMA. It has to be one or the other, for the pair,
- * though different timings can still be chosen for each drive.
- * We could set the appropriate timing bits on the fly,
- * but that might be a bit confusing. So, for now we statically
- * handle this requirement by looking at our mate drive to see
- * what it is capable of, before choosing a mode for our own drive.
- */
- if (mate->present) {
- struct hd_driveid *mateid = mate->id;
- if (mateid && (mateid->capability & 1) && !__ide_dma_bad_drive(mate)) {
- if ((mateid->field_valid & 4) && (mateid->dma_ultra & 7))
- udma_ok = 1;
- else if ((mateid->field_valid & 2) && (mateid->dma_mword & 7))
- udma_ok = 0;
- else
- udma_ok = 1;
- }
+ if (mate->present == 0)
+ goto out;
+
+ if ((mateid->capability & 1) && __ide_dma_bad_drive(mate) == 0) {
+ if ((mateid->field_valid & 4) && (mateid->dma_ultra & 7))
+ goto out;
+ if ((mateid->field_valid & 2) && (mateid->dma_mword & 7))
+ mask = 0;
}
- /*
- * Now see what the current drive is capable of,
- * selecting UDMA only if the mate said it was ok.
- */
- if (id && (id->capability & 1) && hwif->autodma && !__ide_dma_bad_drive(drive)) {
- if (udma_ok && (id->field_valid & 4) && (id->dma_ultra & 7)) {
- if (id->dma_ultra & 4)
- mode = XFER_UDMA_2;
- else if (id->dma_ultra & 2)
- mode = XFER_UDMA_1;
- else if (id->dma_ultra & 1)
- mode = XFER_UDMA_0;
- }
- if (!mode && (id->field_valid & 2) && (id->dma_mword & 7)) {
- if (id->dma_mword & 4)
- mode = XFER_MW_DMA_2;
- else if (id->dma_mword & 2)
- mode = XFER_MW_DMA_1;
- else if (id->dma_mword & 1)
- mode = XFER_MW_DMA_0;
- }
- }
- return mode;
+out:
+ return mask;
}
/*
@@ -250,7 +228,12 @@
*/
static int sc1200_config_dma (ide_drive_t *drive)
{
- return sc1200_config_dma2(drive, sc1200_autoselect_dma_mode(drive));
+ u8 mode = 0;
+
+ if (ide_use_dma(drive))
+ mode = ide_max_dma_mode(drive);
+
+ return sc1200_config_dma2(drive, mode);
}
@@ -461,6 +444,7 @@
hwif->serialized = hwif->mate->serialized = 1;
hwif->autodma = 0;
if (hwif->dma_base) {
+ hwif->udma_filter = sc1200_udma_filter;
hwif->ide_dma_check = &sc1200_config_dma;
hwif->ide_dma_end = &sc1200_ide_dma_end;
if (!noautodma)