---

yaml
---
r: 206102
b: refs/heads/master
c: 253d2e5
h: refs/heads/master
v: v3

[refs]

@@ -1,2 +1,2 @@
 ---
-refs/heads/master: fcd097f31a6ee207cc0c3da9cccd2a86d4334785
+refs/heads/master: 253d2e549818f5a4a52e2db0aba3dacee21e5b38

trunk/drivers/pci/probe.c

@@ -163,16 +163,26 @@ int __pci_read_base(struct pci_dev *dev, enum pci_bar_type type,
 			struct resource *res, unsigned int pos)
 {
 	u32 l, sz, mask;
+	u16 orig_cmd;
 
 	mask = type ? PCI_ROM_ADDRESS_MASK : ~0;
 
+	if (!dev->mmio_always_on) {
+		pci_read_config_word(dev, PCI_COMMAND, &orig_cmd);
+		pci_write_config_word(dev, PCI_COMMAND,
+			orig_cmd & ~(PCI_COMMAND_MEMORY | PCI_COMMAND_IO));
+	}
+
 	res->name = pci_name(dev);
 
 	pci_read_config_dword(dev, pos, &l);
 	pci_write_config_dword(dev, pos, l | mask);
 	pci_read_config_dword(dev, pos, &sz);
 	pci_write_config_dword(dev, pos, l);
 
+	if (!dev->mmio_always_on)
+		pci_write_config_word(dev, PCI_COMMAND, orig_cmd);
+
 	/*
 	 * All bits set in sz means the device isn't working properly.
 	 * If the BAR isn't implemented, all bits must be 0.  If it's a

trunk/drivers/pci/quirks.c

@@ -91,6 +91,19 @@ static void __devinit quirk_resource_alignment(struct pci_dev *dev)
 }
 DECLARE_PCI_FIXUP_HEADER(PCI_ANY_ID, PCI_ANY_ID, quirk_resource_alignment);
 
+/*
+ * Decoding should be disabled for a PCI device during BAR sizing to avoid
+ * conflict. But doing so may cause problems on host bridge and perhaps other
+ * key system devices. For devices that need to have mmio decoding always-on,
+ * we need to set the dev->mmio_always_on bit.
+ */
+static void __devinit quirk_mmio_always_on(struct pci_dev *dev)
+{
+	if ((dev->class >> 8) == PCI_CLASS_BRIDGE_HOST)
+		dev->mmio_always_on = 1;
+}
+DECLARE_PCI_FIXUP_EARLY(PCI_ANY_ID, PCI_ANY_ID, quirk_mmio_always_on);
+
 /* The Mellanox Tavor device gives false positive parity errors
  * Mark this device with a broken_parity_status, to allow
  * PCI scanning code to "skip" this now blacklisted device.

trunk/include/linux/pci.h

@@ -270,6 +270,8 @@ struct pci_dev {
 	unsigned int	d1_support:1;	/* Low power state D1 is supported */
 	unsigned int	d2_support:1;	/* Low power state D2 is supported */
 	unsigned int	no_d1d2:1;	/* Only allow D0 and D3 */
+	unsigned int	mmio_always_on:1;	/* disallow turning off io/mem
+						   decoding during bar sizing */
 	unsigned int	wakeup_prepared:1;
 	unsigned int	d3_delay;	/* D3->D0 transition time in ms */