1 files changed, 15 insertions, 5 deletions

diff --git a/drivers/ide/pci/hpt366.c b/drivers/ide/pci/hpt366.c
index 4f8017ac9900..c33d0b0f11c9 100644
--- a/drivers/ide/pci/hpt366.c
+++ b/drivers/ide/pci/hpt366.c
@@ -1,5 +1,5 @@
 /*
- * linux/drivers/ide/pci/hpt366.c               Version 1.05    Jun 26, 2007
+ * linux/drivers/ide/pci/hpt366.c               Version 1.06    Jun 27, 2007
  *
  * Copyright (C) 1999-2003              Andre Hedrick <andre@linux-ide.org>
  * Portions Copyright (C) 2001          Sun Microsystems, Inc.
@@ -1514,18 +1514,28 @@ static int __devinit init_setup_hpt366(struct pci_dev *dev, ide_pci_device_t *d)
                 goto init_single;
 
         /*
-         * HPT36x chips are single channel and
-         * do not seem to have the channel enable bit...
+         * HPT36x chips have one channel per function and have
+         * both channel enable bits located differently and visible
+         * to both functions -- really stupid design decision... :-(
+         * Bit 4 is for the primary channel, bit 5 for the secondary.
          */
         d->channels = 1;
-        d->enablebits[0].reg = 0;
+        d->enablebits[0].mask = d->enablebits[0].val = 0x10;
 
         if ((dev2 = pci_get_slot(dev->bus, dev->devfn + 1)) != NULL) {
-                u8  pin1 = 0, pin2 = 0;
+                u8  mcr1 = 0, pin1 = 0, pin2 = 0;
                 int ret;
 
                 pci_set_drvdata(dev2, info[rev]);
 
+                /*
+                 * Now we'll have to force both channels enabled if
+                 * at least one of them has been enabled by BIOS...
+                 */
+                pci_read_config_byte(dev, 0x50, &mcr1);
+                if (mcr1 & 0x30)
+                        pci_write_config_byte(dev, 0x50, mcr1 | 0x30);
+
                 pci_read_config_byte(dev,  PCI_INTERRUPT_PIN, &pin1);
                 pci_read_config_byte(dev2, PCI_INTERRUPT_PIN, &pin2);
                 if (pin1 != pin2 && dev->irq == dev2->irq) {