3 files changed, 65 insertions, 15 deletions

diff --git a/drivers/firewire/core-cdev.c b/drivers/firewire/core-cdev.c
index bf03455b6fc2..0d628aa11be5 100644
--- a/drivers/firewire/core-cdev.c
+++ b/drivers/firewire/core-cdev.c
@@ -831,8 +831,10 @@ static int ioctl_send_response(struct client *client, union ioctl_arg *arg)
 
 	r = container_of(resource, struct inbound_transaction_resource,
 			 resource);
-	if (is_fcp_request(r->request))
+	if (is_fcp_request(r->request)) {
+		kfree(r->data);
 		goto out;
+	}
 
 	if (a->length != fw_get_response_length(r->request)) {
 		ret = -EINVAL;
diff --git a/drivers/firewire/core-device.c b/drivers/firewire/core-device.c
index 7c2eed76011e..a293b39fd4ce 100644
--- a/drivers/firewire/core-device.c
+++ b/drivers/firewire/core-device.c
@@ -732,14 +732,11 @@ static void create_units(struct fw_device *device)
 					fw_unit_attributes,
 					&unit->attribute_group);
 
-		if (device_register(&unit->device) < 0)
-			goto skip_unit;
-
 		fw_device_get(device);
-		continue;
-
-	skip_unit:
-		kfree(unit);
+		if (device_register(&unit->device) < 0) {
+			put_device(&unit->device);
+			continue;
+		}
 	}
 }
 
diff --git a/drivers/firewire/ohci.c b/drivers/firewire/ohci.c
index 45c048751f3b..9807a885e698 100644
--- a/drivers/firewire/ohci.c
+++ b/drivers/firewire/ohci.c
@@ -292,6 +292,51 @@ static char ohci_driver_name[] = KBUILD_MODNAME;
 #define QUIRK_TI_SLLZ059		0x20
 #define QUIRK_IR_WAKE			0x40
 
+// On PCI Express Root Complex in any type of AMD Ryzen machine, VIA VT6306/6307/6308 with Asmedia
+// ASM1083/1085 brings an inconvenience that the read accesses to 'Isochronous Cycle Timer' register
+// (at offset 0xf0 in PCI I/O space) often causes unexpected system reboot. The mechanism is not
+// clear, since the read access to the other registers is enough safe; e.g. 'Node ID' register,
+// while it is probable due to detection of any type of PCIe error.
+#define QUIRK_REBOOT_BY_CYCLE_TIMER_READ	0x80000000
+
+#if IS_ENABLED(CONFIG_X86)
+
+static bool has_reboot_by_cycle_timer_read_quirk(const struct fw_ohci *ohci)
+{
+	return !!(ohci->quirks & QUIRK_REBOOT_BY_CYCLE_TIMER_READ);
+}
+
+#define PCI_DEVICE_ID_ASMEDIA_ASM108X	0x1080
+
+static bool detect_vt630x_with_asm1083_on_amd_ryzen_machine(const struct pci_dev *pdev)
+{
+	const struct pci_dev *pcie_to_pci_bridge;
+
+	// Detect any type of AMD Ryzen machine.
+	if (!static_cpu_has(X86_FEATURE_ZEN))
+		return false;
+
+	// Detect VIA VT6306/6307/6308.
+	if (pdev->vendor != PCI_VENDOR_ID_VIA)
+		return false;
+	if (pdev->device != PCI_DEVICE_ID_VIA_VT630X)
+		return false;
+
+	// Detect Asmedia ASM1083/1085.
+	pcie_to_pci_bridge = pdev->bus->self;
+	if (pcie_to_pci_bridge->vendor != PCI_VENDOR_ID_ASMEDIA)
+		return false;
+	if (pcie_to_pci_bridge->device != PCI_DEVICE_ID_ASMEDIA_ASM108X)
+		return false;
+
+	return true;
+}
+
+#else
+#define has_reboot_by_cycle_timer_read_quirk(ohci) false
+#define detect_vt630x_with_asm1083_on_amd_ryzen_machine(pdev)	false
+#endif
+
 /* In case of multiple matches in ohci_quirks[], only the first one is used. */
 static const struct {
 	unsigned short vendor, device, revision, flags;
@@ -1112,7 +1157,7 @@ static void context_tasklet(unsigned long data)
 static int context_add_buffer(struct context *ctx)
 {
 	struct descriptor_buffer *desc;
-	dma_addr_t uninitialized_var(bus_addr);
+	dma_addr_t bus_addr;
 	int offset;
 
 	/*
@@ -1302,7 +1347,7 @@ static int at_context_queue_packet(struct context *ctx,
 				   struct fw_packet *packet)
 {
 	struct fw_ohci *ohci = ctx->ohci;
-	dma_addr_t d_bus, uninitialized_var(payload_bus);
+	dma_addr_t d_bus, payload_bus;
 	struct driver_data *driver_data;
 	struct descriptor *d, *last;
 	__le32 *header;
@@ -1730,6 +1775,9 @@ static u32 get_cycle_time(struct fw_ohci *ohci)
 	s32 diff01, diff12;
 	int i;
 
+	if (has_reboot_by_cycle_timer_read_quirk(ohci))
+		return 0;
+
 	c2 = reg_read(ohci, OHCI1394_IsochronousCycleTimer);
 
 	if (ohci->quirks & QUIRK_CYCLE_TIMER) {
@@ -2458,7 +2506,7 @@ static int ohci_set_config_rom(struct fw_card *card,
 {
 	struct fw_ohci *ohci;
 	__be32 *next_config_rom;
-	dma_addr_t uninitialized_var(next_config_rom_bus);
+	dma_addr_t next_config_rom_bus;
 
 	ohci = fw_ohci(card);
 
@@ -2947,10 +2995,10 @@ static struct fw_iso_context *ohci_allocate_iso_context(struct fw_card *card,
 				int type, int channel, size_t header_size)
 {
 	struct fw_ohci *ohci = fw_ohci(card);
-	struct iso_context *uninitialized_var(ctx);
-	descriptor_callback_t uninitialized_var(callback);
-	u64 *uninitialized_var(channels);
-	u32 *uninitialized_var(mask), uninitialized_var(regs);
+	struct iso_context *ctx;
+	descriptor_callback_t callback;
+	u64 *channels;
+	u32 *mask, regs;
 	int index, ret = -EBUSY;
 
 	spin_lock_irq(&ohci->lock);
@@ -3633,6 +3681,9 @@ static int pci_probe(struct pci_dev *dev,
 	if (param_quirks)
 		ohci->quirks = param_quirks;
 
+	if (detect_vt630x_with_asm1083_on_amd_ryzen_machine(dev))
+		ohci->quirks |= QUIRK_REBOOT_BY_CYCLE_TIMER_READ;
+
 	/*
 	 * Because dma_alloc_coherent() allocates at least one page,
 	 * we save space by using a common buffer for the AR request/