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>

1 files changed, 82 insertions, 36 deletions

diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c
index 7ddcfc65e790..faf02dd00015 100644
--- 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)
 {