X-Git-Url: http://git.onelab.eu/?a=blobdiff_plain;f=drivers%2Fide%2Fpci%2Fpiix.c;h=c4161a5f517e761530905b1e568cc756373eeea4;hb=c7b5ebbddf7bcd3651947760f423e3783bbe6573;hp=26719f2c7932ae776fd490387b18db3377368e59;hpb=a2c21200f1c81b08cb55e417b68150bba439b646;p=linux-2.6.git

diff --git a/drivers/ide/pci/piix.c b/drivers/ide/pci/piix.c
index 26719f2c7..c4161a5f5 100644
--- a/drivers/ide/pci/piix.c
+++ b/drivers/ide/pci/piix.c
@@ -561,36 +561,31 @@ static int piix_config_drive_xfer_rate (ide_drive_t *drive)
 	drive->init_speed = 0;
 
 	if ((id->capability & 1) && drive->autodma) {
+
 		/* Consult the list of known "bad" drives */
 		if (__ide_dma_bad_drive(drive))
 			goto fast_ata_pio;
-		if (id->field_valid & 4) {
-			if (id->dma_ultra & hwif->ultra_mask) {
-				/* Force if Capable UltraDMA */
-				if ((id->field_valid & 2) &&
-				    (!piix_config_drive_for_dma(drive)))
-					goto try_dma_modes;
-			}
-		} else if (id->field_valid & 2) {
-try_dma_modes:
-			if ((id->dma_mword & hwif->mwdma_mask) ||
-			    (id->dma_1word & hwif->swdma_mask)) {
-				/* Force if Capable regular DMA modes */
-				if (!piix_config_drive_for_dma(drive))
-					goto no_dma_set;
-			}
-		} else if (__ide_dma_good_drive(drive) &&
-			   (id->eide_dma_time < 150)) {
-			/* Consult the list of known "good" drives */
-			if (!piix_config_drive_for_dma(drive))
-				goto no_dma_set;
-		} else {
-			goto fast_ata_pio;
+
+		/**
+		 * Try to turn DMA on if:
+		 *  - UDMA or EIDE modes are supported or
+		 *  - drive is a known "good" drive
+		 *
+		 * Checks for best mode supported are down later by
+		 * piix_config_drive_for_dma() -> ide_dma_speed()
+		 */
+		if ((id->field_valid & (4 | 2)) ||
+		    (__ide_dma_good_drive(drive) && id->eide_dma_time < 150)) {
+			if (piix_config_drive_for_dma(drive))
+				return hwif->ide_dma_on(drive);
 		}
-		return hwif->ide_dma_on(drive);
+
+		/* For some reason DMA wasn't turned on, so try PIO. */
+		goto fast_ata_pio;
+
 	} else if ((id->capability & 8) || (id->field_valid & 2)) {
 fast_ata_pio:
-no_dma_set:
+		/* Find best PIO mode. */
 		hwif->tuneproc(drive, 255);
 		return hwif->ide_dma_off_quietly(drive);
 	}
@@ -803,7 +798,7 @@ static struct pci_device_id piix_pci_tbl[] = {
 MODULE_DEVICE_TABLE(pci, piix_pci_tbl);
 
 static struct pci_driver driver = {
-	.name		= "PIIX IDE",
+	.name		= "PIIX_IDE",
 	.id_table	= piix_pci_tbl,
 	.probe		= piix_init_one,
 };