adjust legacy IDE resource setting (v2)

The change to force legacy mode IDE channels' resources to fixed non-zero
values confuses (at least some versions of) X, because the values reported
by the kernel and those readable from PCI config space aren't consistent
anymore.  Therefore, this patch arranges for the respective BARs to also
get updated if possible.
Signed-off-by: Jan Beulich <jbeulich@novell.com>
Acked-by: Alan Cox <alan@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>

drivers/pci/probe.c

@@ -682,7 +682,34 @@ static void pci_read_irq(struct pci_dev *dev)
 	dev->irq = irq;
 }
 
-#define LEGACY_IO_RESOURCE	(IORESOURCE_IO | IORESOURCE_PCI_FIXED)
+static void change_legacy_io_resource(struct pci_dev * dev, unsigned index,
+                                      unsigned start, unsigned end)
+{
+	unsigned base = start & PCI_BASE_ADDRESS_IO_MASK;
+	unsigned len = (end | ~PCI_BASE_ADDRESS_IO_MASK) - base + 1;
+
+	/*
+	 * Some X versions get confused when the BARs reported through
+	 * /sys or /proc differ from those seen in config space, thus
+	 * try to update the config space values, too.
+	 */
+	if (!(pci_resource_flags(dev, index) & IORESOURCE_IO))
+		printk(KERN_WARNING "%s: cannot adjust BAR%u (not I/O)\n",
+		       pci_name(dev), index);
+	else if (pci_resource_len(dev, index) != len)
+		printk(KERN_WARNING "%s: cannot adjust BAR%u (size %04X)\n",
+		       pci_name(dev), index, (unsigned)pci_resource_len(dev, index));
+	else {
+		printk(KERN_INFO "%s: trying to change BAR%u from %04X to %04X\n",
+		       pci_name(dev), index,
+		       (unsigned)pci_resource_start(dev, index), base);
+		pci_write_config_dword(dev, PCI_BASE_ADDRESS_0 + index * 4, base);
+	}
+	pci_resource_start(dev, index) = start;
+	pci_resource_end(dev, index)   = end;
+	pci_resource_flags(dev, index) =
+		IORESOURCE_IO | IORESOURCE_PCI_FIXED | PCI_BASE_ADDRESS_SPACE_IO;
+}
 
 /**
  * pci_setup_device - fill in class and map information of a device
@@ -735,20 +762,12 @@ static int pci_setup_device(struct pci_dev * dev)
 			u8 progif;
 			pci_read_config_byte(dev, PCI_CLASS_PROG, &progif);
 			if ((progif & 1) == 0) {
-				dev->resource[0].start = 0x1F0;
-				dev->resource[0].end = 0x1F7;
-				dev->resource[0].flags = LEGACY_IO_RESOURCE;
-				dev->resource[1].start = 0x3F6;
-				dev->resource[1].end = 0x3F6;
-				dev->resource[1].flags = LEGACY_IO_RESOURCE;
+				change_legacy_io_resource(dev, 0, 0x1F0, 0x1F7);
+				change_legacy_io_resource(dev, 1, 0x3F6, 0x3F6);
 			}
 			if ((progif & 4) == 0) {
-				dev->resource[2].start = 0x170;
-				dev->resource[2].end = 0x177;
-				dev->resource[2].flags = LEGACY_IO_RESOURCE;
-				dev->resource[3].start = 0x376;
-				dev->resource[3].end = 0x376;
-				dev->resource[3].flags = LEGACY_IO_RESOURCE;
+				change_legacy_io_resource(dev, 2, 0x170, 0x177);
+				change_legacy_io_resource(dev, 3, 0x376, 0x376);
 			}
 		}
 		break;