The driver's ide_dma_test_irq() method was reading the MRDMODE register even on PCI0643/6 where it was write-only -- fix this by always reading the "backward- compatible" interrupt bits, renaming dma_alt_stat to irq_stat as these interrupt status bits are not coupled to DMA. In addition, wrong interrupt bit was tested/cleared for the primary channel -- it's bit 2 in all the chip specs and the driver used bit 1... :-/ --- Warning: as usual, this has only been compile-tested. :-) drivers/ide/pci/cmd64x.c | 24 ++++++++++++------------ 1 files changed, 12 insertions(+), 12 deletions(-) Index: linux-2.6/drivers/ide/pci/cmd64x.c =================================================================== --- linux-2.6.orig/drivers/ide/pci/cmd64x.c +++ linux-2.6/drivers/ide/pci/cmd64x.c @@ -1,6 +1,6 @@ /* $Id: cmd64x.c,v 1.21 2000/01/30 23:23:16 * - * linux/drivers/ide/pci/cmd64x.c Version 1.43 Feb 8, 2007 + * linux/drivers/ide/pci/cmd64x.c Version 1.44 Feb 13, 2007 * * cmd64x.c: Enable interrupts at initialization time on Ultra/PCI machines. * Note, this driver is not used at all on other systems because @@ -39,7 +39,7 @@ * CMD64x specific registers definition. */ #define CFR 0x50 -#define CFR_INTR_CH0 0x02 +#define CFR_INTR_CH0 0x04 #define CNTRL 0x51 #define CNTRL_DIS_RA0 0x40 #define CNTRL_DIS_RA1 0x80 @@ -510,19 +510,19 @@ static int cmd64x_ide_dma_end (ide_drive static int cmd64x_ide_dma_test_irq (ide_drive_t *drive) { - ide_hwif_t *hwif = HWIF(drive); - struct pci_dev *dev = hwif->pci_dev; - u8 dma_alt_stat = 0, mask = (hwif->channel) ? MRDMODE_INTR_CH1 : - MRDMODE_INTR_CH0; - u8 dma_stat = hwif->INB(hwif->dma_status); + ide_hwif_t *hwif = HWIF(drive); + struct pci_dev *dev = hwif->pci_dev; + u8 irq_reg = hwif->channel ? ARTTIM23 : CFR; + u8 irq_stat = 0, mask = hwif->channel ? ARTTIM23_INTR_CH1 : CFR_INTR_CH0; + u8 dma_stat = hwif->INB(hwif->dma_status); + + (void) pci_read_config_byte(dev, irq_reg, &irq_stat); - (void) pci_read_config_byte(dev, MRDMODE, &dma_alt_stat); #ifdef DEBUG - printk("%s: dma_stat: 0x%02x dma_alt_stat: " - "0x%02x mask: 0x%02x\n", drive->name, - dma_stat, dma_alt_stat, mask); + printk("%s: dma_stat: 0x%02x irq_stat: 0x%02x mask: 0x%02x\n", + drive->name, dma_stat, irq_stat, mask); #endif - if (!(dma_alt_stat & mask)) + if (!(irq_stat & mask)) return 0; /* return 1 if INTR asserted */ - To unsubscribe from this list: send the line "unsubscribe linux-ide" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html