PCI: don't enable too much HT MSI mapping

Impact: fix bug

Prakash reported that his c51-mcp51 system ondie sound card doesn't work
MSI but if he hack out the HT-MSI on mcp51, the MSI will work well with
sound card.

This patch reworks nv_msi_ht_cap_quirk() and will only avoid enabling
ht_msi on devices following that root device.

Reported-by: Prakash Punnoor <prakash@punnoor.de>
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>

diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c
index 7ddcfc65e7903fb4fa807c9745fed66fea6950c0..faf02dd00015744abcdad1b7d3daf4c4f331106f 100644 (file)
--- a/drivers/pci/quirks.c
+++ b/drivers/pci/quirks.c
@@ -2147,6 +2147,65 @@ DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_NVIDIA,
                        PCI_DEVICE_ID_NVIDIA_NVENET_15,
                        nvenet_msi_disable);
 
+static int __devinit ht_check_msi_mapping(struct pci_dev *dev)
+{
+       int pos, ttl = 48;
+       int found = 0;
+
+       /* check if there is HT MSI cap or enabled on this device */
+       pos = pci_find_ht_capability(dev, HT_CAPTYPE_MSI_MAPPING);
+       while (pos && ttl--) {
+               u8 flags;
+
+               if (found < 1)
+                       found = 1;
+               if (pci_read_config_byte(dev, pos + HT_MSI_FLAGS,
+                                        &flags) == 0) {
+                       if (flags & HT_MSI_FLAGS_ENABLE) {
+                               if (found < 2) {
+                                       found = 2;
+                                       break;
+                               }
+                       }
+               }
+               pos = pci_find_next_ht_capability(dev, pos,
+                                                 HT_CAPTYPE_MSI_MAPPING);
+       }
+
+       return found;
+}
+
+static int __devinit host_bridge_with_leaf(struct pci_dev *host_bridge)
+{
+       struct pci_dev *dev;
+       int pos;
+       int i, dev_no;
+       int found = 0;
+
+       dev_no = host_bridge->devfn >> 3;
+       for (i = dev_no + 1; i < 0x20; i++) {
+               dev = pci_get_slot(host_bridge->bus, PCI_DEVFN(i, 0));
+               if (!dev)
+                       continue;
+
+               /* found next host bridge ?*/
+               pos = pci_find_ht_capability(dev, HT_CAPTYPE_SLAVE);
+               if (pos != 0) {
+                       pci_dev_put(dev);
+                       break;
+               }
+
+               if (ht_check_msi_mapping(dev)) {
+                       found = 1;
+                       pci_dev_put(dev);
+                       break;
+               }
+               pci_dev_put(dev);
+       }
+
+       return found;
+}
+
 static void __devinit nv_ht_enable_msi_mapping(struct pci_dev *dev)
 {
        struct pci_dev *host_bridge;
@@ -2171,6 +2230,10 @@ static void __devinit nv_ht_enable_msi_mapping(struct pci_dev *dev)
        if (!found)
                return;
 
+       /* don't enable host_bridge with leaf directly here */
+       if (host_bridge == dev && host_bridge_with_leaf(host_bridge))
+               goto out;
+
        /* root did that ! */
        if (msi_ht_cap_enabled(host_bridge))
                goto out;
@@ -2201,44 +2264,12 @@ static void __devinit ht_disable_msi_mapping(struct pci_dev *dev)
        }
 }
 
-static int __devinit ht_check_msi_mapping(struct pci_dev *dev)
-{
-       int pos, ttl = 48;
-       int found = 0;
-
-       /* check if there is HT MSI cap or enabled on this device */
-       pos = pci_find_ht_capability(dev, HT_CAPTYPE_MSI_MAPPING);
-       while (pos && ttl--) {
-               u8 flags;
-
-               if (found < 1)
-                       found = 1;
-               if (pci_read_config_byte(dev, pos + HT_MSI_FLAGS,
-                                        &flags) == 0) {
-                       if (flags & HT_MSI_FLAGS_ENABLE) {
-                               if (found < 2) {
-                                       found = 2;
-                                       break;
-                               }
-                       }
-               }
-               pos = pci_find_next_ht_capability(dev, pos,
-                                                 HT_CAPTYPE_MSI_MAPPING);
-       }
-
-       return found;
-}
-
-static void __devinit nv_msi_ht_cap_quirk(struct pci_dev *dev)
+static void __devinit __nv_msi_ht_cap_quirk(struct pci_dev *dev, int all)
 {
        struct pci_dev *host_bridge;
        int pos;
        int found;
 
-       /* Enabling HT MSI mapping on this device breaks MCP51 */
-       if (dev->device == 0x270)
-               return;
-
        /* check if there is HT MSI cap or enabled on this device */
        found = ht_check_msi_mapping(dev);
 
@@ -2262,7 +2293,10 @@ static void __devinit nv_msi_ht_cap_quirk(struct pci_dev *dev)
                /* Host bridge is to HT */
                if (found == 1) {
                        /* it is not enabled, try to enable it */
-                       nv_ht_enable_msi_mapping(dev);
+                       if (all)
+                               ht_enable_msi_mapping(dev);
+                       else
+                               nv_ht_enable_msi_mapping(dev);
                }
                return;
        }
@@ -2274,8 +2308,20 @@ static void __devinit nv_msi_ht_cap_quirk(struct pci_dev *dev)
        /* Host bridge is not to HT, disable HT MSI mapping on this device */
        ht_disable_msi_mapping(dev);
 }
-DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_NVIDIA, PCI_ANY_ID, nv_msi_ht_cap_quirk);
-DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_AL, PCI_ANY_ID, nv_msi_ht_cap_quirk);
+
+static void __devinit nv_msi_ht_cap_quirk_all(struct pci_dev *dev)
+{
+       return __nv_msi_ht_cap_quirk(dev, 1);
+}
+
+static void __devinit nv_msi_ht_cap_quirk_leaf(struct pci_dev *dev)
+{
+       return __nv_msi_ht_cap_quirk(dev, 0);
+}
+
+DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_NVIDIA, PCI_ANY_ID, nv_msi_ht_cap_quirk_leaf);
+
+DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_AL, PCI_ANY_ID, nv_msi_ht_cap_quirk_all);
 
 static void __devinit quirk_msi_intx_disable_bug(struct pci_dev *dev)
 {