From 5fd216bbb277b645109a889c489e13a7aafbc304 Mon Sep 17 00:00:00 2001 From: Bartlomiej Zolnierkiewicz Date: Wed, 16 May 2007 00:51:43 +0200 Subject: 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 --- drivers/ide/pci/sc1200.c | 86 ++++++++++++++++++++---------------------------- 1 file changed, 35 insertions(+), 51 deletions(-) (limited to 'drivers/ide/pci/sc1200.c') diff --git a/drivers/ide/pci/sc1200.c b/drivers/ide/pci/sc1200.c index b5ae0c50e21..c0254b5e7d9 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 + * 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 @@ static const unsigned int sc1200_pio_timings[4][5] = */ //#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; - - /* - * 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; - } - } - /* - * 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; - } + 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; + + 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; } - return mode; +out: + return mask; } /* @@ -250,7 +228,12 @@ static int sc1200_config_dma2 (ide_drive_t *drive, int mode) */ 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 @@ static void __devinit init_hwif_sc1200 (ide_hwif_t *hwif) 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) -- cgit v1.2.3