ide: clear bmdma status in ide_intr() for ICHx controllers (revised #4)

patch 1/2 (revised):
- Fix drive->waiting_for_dma to work with CDB-intr devices.
- Do the dma status clearing in ide_intr() and add a new
  hwif->ide_dma_clear_irq for Intel ICHx controllers.

Revised per Alan, Sergei and Bart's advice.

Patch against 2.6.20-rc6. Tested ok on my ICH4 and pdc20275 adapters.
Please review/apply, thanks.

Signed-off-by: Albert Lee <albertcc@tw.ibm.com>
Cc: Sergei Shtylyov <sshtylyov@ru.mvista.com>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: "Adam W. Hawks" <awhawks@us.ibm.com>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>

1 files changed, 48 insertions, 15 deletions

diff --git a/drivers/ide/pci/piix.c b/drivers/ide/pci/piix.c
index 52cfc2ac22c..af65b0888bb 100644
--- a/drivers/ide/pci/piix.c
+++ b/drivers/ide/pci/piix.c
@@ -410,17 +410,14 @@ fast_ata_pio:
 }
 
 /**
- *	init_chipset_piix	-	set up the PIIX chipset
- *	@dev: PCI device to set up
- *	@name: Name of the device
+ *	piix_is_ichx	-	check if ICHx
+ *	@dev: PCI device to check
  *
- *	Initialize the PCI device as required. For the PIIX this turns
- *	out to be nice and simple
+ *	returns 1 if ICHx, 0 otherwise.
  */
- 
-static unsigned int __devinit init_chipset_piix (struct pci_dev *dev, const char *name)
+static int piix_is_ichx(struct pci_dev *dev)
 {
-        switch(dev->device) {
+        switch (dev->device) {
 		case PCI_DEVICE_ID_INTEL_82801EB_1:
 		case PCI_DEVICE_ID_INTEL_82801AA_1:
 		case PCI_DEVICE_ID_INTEL_82801AB_1:
@@ -438,19 +435,51 @@ static unsigned int __devinit init_chipset_piix (struct pci_dev *dev, const char
 		case PCI_DEVICE_ID_INTEL_ICH7_21:
 		case PCI_DEVICE_ID_INTEL_ESB2_18:
 		case PCI_DEVICE_ID_INTEL_ICH8_6:
-		{
-			unsigned int extra = 0;
-			pci_read_config_dword(dev, 0x54, &extra);
-			pci_write_config_dword(dev, 0x54, extra|0x400);
-		}
-		default:
-			break;
+			return 1;
 	}
 
 	return 0;
 }
 
 /**
+ *	init_chipset_piix	-	set up the PIIX chipset
+ *	@dev: PCI device to set up
+ *	@name: Name of the device
+ *
+ *	Initialize the PCI device as required. For the PIIX this turns
+ *	out to be nice and simple
+ */
+
+static unsigned int __devinit init_chipset_piix (struct pci_dev *dev, const char *name)
+{
+	if (piix_is_ichx(dev)) {
+		unsigned int extra = 0;
+		pci_read_config_dword(dev, 0x54, &extra);
+		pci_write_config_dword(dev, 0x54, extra|0x400);
+	}
+
+	return 0;
+}
+
+/**
+ *	piix_dma_clear_irq	-	clear BMDMA status
+ *	@drive: IDE drive to clear
+ *
+ *	Called from ide_intr() for PIO interrupts
+ *	to clear BMDMA status as needed by ICHx
+ */
+static void piix_dma_clear_irq(ide_drive_t *drive)
+{
+	ide_hwif_t *hwif = HWIF(drive);
+	u8 dma_stat;
+
+	/* clear the INTR & ERROR bits */
+	dma_stat = hwif->INB(hwif->dma_status);
+	/* Should we force the bit as well ? */
+	hwif->OUTB(dma_stat, hwif->dma_status);
+}
+
+/**
  *	init_hwif_piix		-	fill in the hwif for the PIIX
  *	@hwif: IDE interface
  *
@@ -486,6 +515,10 @@ static void __devinit init_hwif_piix(ide_hwif_t *hwif)
 	if (!hwif->dma_base)
 		return;
 
+	/* ICHx need to clear the bmdma status for all interrupts */
+	if (piix_is_ichx(hwif->pci_dev))
+		hwif->ide_dma_clear_irq = &piix_dma_clear_irq;
+
 	hwif->atapi_dma = 1;
 	hwif->ultra_mask = 0x3f;
 	hwif->mwdma_mask = 0x06;