Ticket #5551: ehci_sb600.diff

src/add-ons/kernel/busses/usb/ehci.cpp

@@ -134 +134 @@
     TRACE("constructing new EHCI host controller driver\n");
     fInitOK = false;
 
+    // ATI/AMD SB600/SB700 freeze workaround kindly borrowed from NetBSD PR40056
+    if (fPCIInfo->vendor_id == 0x1002 /* ATI/AMD */) {
+        bool applyWorkaround = false;
+
+        if (fPCIInfo->device_id == 0x4386 /* SB600 EHCI controller */) {
+            // always apply on SB600
+            applyWorkaround = true;
+        } else if (fPCIInfo->device_id == 0x4396 /* SB700/SB800 EHCI */) {
+            // only apply on certain chipsets, determined by SMBus revision
+            pci_info smbus;
+            int32 index = 0;
+            while (sPCIModule->get_nth_pci_info(index++, &smbus) >= B_OK) {
+                if (smbus.vendor_id == 0x1002 && smbus.device_id == 0x4385) {
+                    /* SB600/SB700/SB800 SMBus controller */
+                    if (smbus.revision == 0x3a || smbus.revision == 0x3b)
+                        applyWorkaround = true;
+
+                    break;
+                }
+            }
+        }
+
+        if (applyWorkaround) {
+            // "reserved" as far as documentation is concerned apparently,
+            // no real idea who figured that out how, but it's in the NetBSD
+            // patch concerning this...
+
+            TRACE_ALWAYS("applying SB600/SB700 freeze workaround\n");
+            uint32 workaround = sPCIModule->read_pci_config(fPCIInfo->bus,
+                fPCIInfo->device, fPCIInfo->function, 0x50, 4);
+
+            sPCIModule->write_pci_config(fPCIInfo->bus, fPCIInfo->device,
+                fPCIInfo->function, 0x50, 4, workaround | (1 << 27));
+        }
+    }
+
     // enable busmaster and memory mapped access
     uint16 command = sPCIModule->read_pci_config(fPCIInfo->bus,
         fPCIInfo->device, fPCIInfo->function, PCI_command, 2);