[PATCH 06/24] thunderbolt: Introduce thunderbolt bus and connection manager

From: Mika Westerberg
Date: Thu May 18 2017 - 10:40:41 EST

Thunderbolt fabric consists of one or more switches. This fabric is
called domain and it is controlled by an entity called connection
manager. The connection manager can be either internal (driven by a
firmware running on the host controller) or external (software driver).
This driver currently implements support for the latter.

In order to manage switches and their properties more easily we model
this domain structure as a Linux bus. Each host controller adds a domain
device to this bus, and these devices are named as domainN where N
stands for index or id of the current domain.

We then abstract connection manager specific operations into a new
structure tb_cm_ops and convert the existing tb.c to fill those
accordingly. This makes it easier to add support for the internal
connection manager in subsequent patches.

Signed-off-by: Mika Westerberg <mika.westerberg@xxxxxxxxxxxxxxx>
Reviewed-by: Yehezkel Bernat <yehezkel.bernat@xxxxxxxxx>
Reviewed-by: Michael Jamet <michael.jamet@xxxxxxxxx>
---
drivers/thunderbolt/Makefile | 2 +-
drivers/thunderbolt/domain.c | 230 +++++++++++++++++++++++++++++++++++++++
drivers/thunderbolt/nhi.c | 31 ++++--
drivers/thunderbolt/tb.c | 156 ++++++++++++--------------
drivers/thunderbolt/tb.h | 70 +++++++++---
drivers/thunderbolt/tunnel_pci.c | 9 +-
6 files changed, 377 insertions(+), 121 deletions(-)
create mode 100644 drivers/thunderbolt/domain.c

diff --git a/drivers/thunderbolt/Makefile b/drivers/thunderbolt/Makefile
index 5d1053cdfa54..e276a9a62261 100644
--- a/drivers/thunderbolt/Makefile
+++ b/drivers/thunderbolt/Makefile
@@ -1,3 +1,3 @@
obj-${CONFIG_THUNDERBOLT} := thunderbolt.o
thunderbolt-objs := nhi.o ctl.o tb.o switch.o cap.o path.o tunnel_pci.o eeprom.o
-
+thunderbolt-objs += domain.o
diff --git a/drivers/thunderbolt/domain.c b/drivers/thunderbolt/domain.c
new file mode 100644
index 000000000000..b5bfca95415d
--- /dev/null
+++ b/drivers/thunderbolt/domain.c
@@ -0,0 +1,230 @@
+/*
+ * Thunderbolt bus support
+ *
+ * Copyright (C) 2017, Intel Corporation
+ * Author: Mika Westerberg <mika.westerberg@xxxxxxxxxxxxxxx>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/device.h>
+#include <linux/idr.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+
+#include "tb.h"
+
+static DEFINE_IDA(tb_domain_ida);
+
+struct bus_type tb_bus_type = {
+ .name = "thunderbolt",
+};
+
+static void tb_domain_release(struct device *dev)
+{
+ struct tb *tb = container_of(dev, struct tb, dev);
+
+ if (tb->ctl)
+ tb_ctl_free(tb->ctl);
+
+ destroy_workqueue(tb->wq);
+ ida_simple_remove(&tb_domain_ida, tb->index);
+ kfree(tb);
+}
+
+struct device_type tb_domain_type = {
+ .name = "thunderbolt_domain",
+ .release = tb_domain_release,
+};
+
+/**
+ * tb_domain_alloc() - Allocate a domain
+ * @nhi: Pointer to the host controller
+ * @privsize: Size of the connection manager private data
+ *
+ * Allocates and initializes a new Thunderbolt domain. Connection
+ * managers are expected to call this and then fill in @cm_ops
+ * accordingly.
+ *
+ * Call tb_domain_put() to release the domain before it has been added
+ * to the system.
+ *
+ * Return: allocated domain structure on %NULL in case of error
+ */
+struct tb *tb_domain_alloc(struct tb_nhi *nhi, size_t privsize)
+{
+ struct tb *tb;
+
+ /*
+ * Make sure the structure sizes map with that the hardware
+ * expects because bit-fields are being used.
+ */
+ BUILD_BUG_ON(sizeof(struct tb_regs_switch_header) != 5 * 4);
+ BUILD_BUG_ON(sizeof(struct tb_regs_port_header) != 8 * 4);
+ BUILD_BUG_ON(sizeof(struct tb_regs_hop) != 2 * 4);
+
+ tb = kzalloc(sizeof(*tb) + privsize, GFP_KERNEL);
+ if (!tb)
+ return NULL;
+
+ tb->nhi = nhi;
+ mutex_init(&tb->lock);
+
+ tb->index = ida_simple_get(&tb_domain_ida, 0, 0, GFP_KERNEL);
+ if (tb->index < 0)
+ goto err_free;
+
+ tb->wq = alloc_ordered_workqueue("thunderbolt%d", 0, tb->index);
+ if (!tb->wq)
+ goto err_remove_ida;
+
+ tb->dev.parent = &nhi->pdev->dev;
+ tb->dev.bus = &tb_bus_type;
+ tb->dev.type = &tb_domain_type;
+ dev_set_name(&tb->dev, "domain%d", tb->index);
+ device_initialize(&tb->dev);
+
+ return tb;
+
+err_remove_ida:
+ ida_simple_remove(&tb_domain_ida, tb->index);
+err_free:
+ kfree(tb);
+
+ return NULL;
+}
+
+/**
+ * tb_domain_add() - Add domain to the system
+ * @tb: Domain to add
+ *
+ * Starts the domain and adds it to the system. Hotplugging devices will
+ * work after this has been returned successfully. In order to remove
+ * and release the domain after this function has been called, call
+ * tb_domain_remove().
+ *
+ * Return: %0 in case of success and negative errno in case of error
+ */
+int tb_domain_add(struct tb *tb)
+{
+ int ret;
+
+ if (WARN_ON(!tb->cm_ops))
+ return -EINVAL;
+
+ mutex_lock(&tb->lock);
+
+ tb->ctl = tb_ctl_alloc(tb->nhi, tb->cm_ops->hotplug, tb);
+ if (!tb->ctl) {
+ ret = -ENOMEM;
+ goto err_unlock;
+ }
+
+ /*
+ * tb_schedule_hotplug_handler may be called as soon as the config
+ * channel is started. Thats why we have to hold the lock here.
+ */
+ tb_ctl_start(tb->ctl);
+
+ ret = device_add(&tb->dev);
+ if (ret)
+ goto err_ctl_stop;
+
+ /* Start the domain */
+ if (tb->cm_ops->start) {
+ ret = tb->cm_ops->start(tb);
+ if (ret)
+ goto err_domain_del;
+ }
+
+ /* This starts event processing */
+ mutex_unlock(&tb->lock);
+
+ return 0;
+
+err_domain_del:
+ device_del(&tb->dev);
+err_ctl_stop:
+ tb_ctl_stop(tb->ctl);
+err_unlock:
+ mutex_unlock(&tb->lock);
+
+ return ret;
+}
+
+/**
+ * tb_domain_remove() - Removes and releases a domain
+ * @tb: Domain to remove
+ *
+ * Stops the domain, removes it from the system and releases all
+ * resources once the last reference has been released.
+ */
+void tb_domain_remove(struct tb *tb)
+{
+ mutex_lock(&tb->lock);
+ if (tb->cm_ops->stop)
+ tb->cm_ops->stop(tb);
+ /* Stop the domain control traffic */
+ tb_ctl_stop(tb->ctl);
+ mutex_unlock(&tb->lock);
+
+ flush_workqueue(tb->wq);
+ device_unregister(&tb->dev);
+}
+
+/**
+ * tb_domain_suspend_noirq() - Suspend a domain
+ * @tb: Domain to suspend
+ *
+ * Suspends all devices in the domain and stops the control channel.
+ */
+int tb_domain_suspend_noirq(struct tb *tb)
+{
+ int ret = 0;
+
+ /*
+ * The control channel interrupt is left enabled during suspend
+ * and taking the lock here prevents any events happening before
+ * we actually have stopped the domain and the control channel.
+ */
+ mutex_lock(&tb->lock);
+ if (tb->cm_ops->suspend_noirq)
+ ret = tb->cm_ops->suspend_noirq(tb);
+ if (!ret)
+ tb_ctl_stop(tb->ctl);
+ mutex_unlock(&tb->lock);
+
+ return ret;
+}
+
+/**
+ * tb_domain_resume_noirq() - Resume a domain
+ * @tb: Domain to resume
+ *
+ * Re-starts the control channel, and resumes all devices connected to
+ * the domain.
+ */
+int tb_domain_resume_noirq(struct tb *tb)
+{
+ int ret = 0;
+
+ mutex_lock(&tb->lock);
+ tb_ctl_start(tb->ctl);
+ if (tb->cm_ops->resume_noirq)
+ ret = tb->cm_ops->resume_noirq(tb);
+ mutex_unlock(&tb->lock);
+
+ return ret;
+}
+
+int tb_domain_init(void)
+{
+ return bus_register(&tb_bus_type);
+}
+
+void tb_domain_exit(void)
+{
+ bus_unregister(&tb_bus_type);
+}
diff --git a/drivers/thunderbolt/nhi.c b/drivers/thunderbolt/nhi.c
index 17f3b1bdb7da..bf69ee42da68 100644
--- a/drivers/thunderbolt/nhi.c
+++ b/drivers/thunderbolt/nhi.c
@@ -589,16 +589,16 @@ static int nhi_suspend_noirq(struct device *dev)
{
struct pci_dev *pdev = to_pci_dev(dev);
struct tb *tb = pci_get_drvdata(pdev);
- thunderbolt_suspend(tb);
- return 0;
+
+ return tb_domain_suspend_noirq(tb);
}

static int nhi_resume_noirq(struct device *dev)
{
struct pci_dev *pdev = to_pci_dev(dev);
struct tb *tb = pci_get_drvdata(pdev);
- thunderbolt_resume(tb);
- return 0;
+
+ return tb_domain_resume_noirq(tb);
}

static void nhi_shutdown(struct tb_nhi *nhi)
@@ -717,12 +717,17 @@ static int nhi_probe(struct pci_dev *pdev, const struct pci_device_id *id)
iowrite32(3906250 / 10000, nhi->iobase + 0x38c00);

dev_info(&nhi->pdev->dev, "NHI initialized, starting thunderbolt\n");
- tb = thunderbolt_alloc_and_start(nhi);
- if (!tb) {
+ tb = tb_probe(nhi);
+ if (!tb)
+ return -ENODEV;
+
+ res = tb_domain_add(tb);
+ if (res) {
/*
* At this point the RX/TX rings might already have been
* activated. Do a proper shutdown.
*/
+ tb_domain_put(tb);
nhi_shutdown(nhi);
return -EIO;
}
@@ -735,7 +740,8 @@ static void nhi_remove(struct pci_dev *pdev)
{
struct tb *tb = pci_get_drvdata(pdev);
struct tb_nhi *nhi = tb->nhi;
- thunderbolt_shutdown_and_free(tb);
+
+ tb_domain_remove(tb);
nhi_shutdown(nhi);
}

@@ -799,14 +805,23 @@ static struct pci_driver nhi_driver = {

static int __init nhi_init(void)
{
+ int ret;
+
if (!dmi_match(DMI_BOARD_VENDOR, "Apple Inc."))
return -ENOSYS;
- return pci_register_driver(&nhi_driver);
+ ret = tb_domain_init();
+ if (ret)
+ return ret;
+ ret = pci_register_driver(&nhi_driver);
+ if (ret)
+ tb_domain_exit();
+ return ret;
}

static void __exit nhi_unload(void)
{
pci_unregister_driver(&nhi_driver);
+ tb_domain_exit();
}

module_init(nhi_init);
diff --git a/drivers/thunderbolt/tb.c b/drivers/thunderbolt/tb.c
index 6b44076e1380..9f00a0f28d53 100644
--- a/drivers/thunderbolt/tb.c
+++ b/drivers/thunderbolt/tb.c
@@ -12,6 +12,18 @@
#include "tb_regs.h"
#include "tunnel_pci.h"

+/**
+ * struct tb_cm - Simple Thunderbolt connection manager
+ * @tunnel_list: List of active tunnels
+ * @hotplug_active: tb_handle_hotplug will stop progressing plug
+ * events and exit if this is not set (it needs to
+ * acquire the lock one more time). Used to drain wq
+ * after cfg has been paused.
+ */
+struct tb_cm {
+ struct list_head tunnel_list;
+ bool hotplug_active;
+};

/* enumeration & hot plug handling */

@@ -62,12 +74,14 @@ static void tb_scan_port(struct tb_port *port)
*/
static void tb_free_invalid_tunnels(struct tb *tb)
{
+ struct tb_cm *tcm = tb_priv(tb);
struct tb_pci_tunnel *tunnel;
struct tb_pci_tunnel *n;
- list_for_each_entry_safe(tunnel, n, &tb->tunnel_list, list)
- {
+
+ list_for_each_entry_safe(tunnel, n, &tcm->tunnel_list, list) {
if (tb_pci_is_invalid(tunnel)) {
tb_pci_deactivate(tunnel);
+ list_del(&tunnel->list);
tb_pci_free(tunnel);
}
}
@@ -149,6 +163,8 @@ static void tb_activate_pcie_devices(struct tb *tb)
struct tb_port *up_port;
struct tb_port *down_port;
struct tb_pci_tunnel *tunnel;
+ struct tb_cm *tcm = tb_priv(tb);
+
/* scan for pcie devices at depth 1*/
for (i = 1; i <= tb->root_switch->config.max_port_number; i++) {
if (tb_is_upstream_port(&tb->root_switch->ports[i]))
@@ -195,6 +211,7 @@ static void tb_activate_pcie_devices(struct tb *tb)
tb_pci_free(tunnel);
}

+ list_add(&tunnel->list, &tcm->tunnel_list);
}
}

@@ -217,10 +234,11 @@ static void tb_handle_hotplug(struct work_struct *work)
{
struct tb_hotplug_event *ev = container_of(work, typeof(*ev), work);
struct tb *tb = ev->tb;
+ struct tb_cm *tcm = tb_priv(tb);
struct tb_switch *sw;
struct tb_port *port;
mutex_lock(&tb->lock);
- if (!tb->hotplug_active)
+ if (!tcm->hotplug_active)
goto out; /* during init, suspend or shutdown */

sw = get_switch_at_route(tb->root_switch, ev->route);
@@ -296,22 +314,14 @@ static void tb_schedule_hotplug_handler(void *data, u64 route, u8 port,
queue_work(tb->wq, &ev->work);
}

-/**
- * thunderbolt_shutdown_and_free() - shutdown everything
- *
- * Free all switches and the config channel.
- *
- * Used in the error path of thunderbolt_alloc_and_start.
- */
-void thunderbolt_shutdown_and_free(struct tb *tb)
+static void tb_stop(struct tb *tb)
{
+ struct tb_cm *tcm = tb_priv(tb);
struct tb_pci_tunnel *tunnel;
struct tb_pci_tunnel *n;

- mutex_lock(&tb->lock);
-
/* tunnels are only present after everything has been initialized */
- list_for_each_entry_safe(tunnel, n, &tb->tunnel_list, list) {
+ list_for_each_entry_safe(tunnel, n, &tcm->tunnel_list, list) {
tb_pci_deactivate(tunnel);
tb_pci_free(tunnel);
}
@@ -320,98 +330,44 @@ void thunderbolt_shutdown_and_free(struct tb *tb)
tb_switch_free(tb->root_switch);
tb->root_switch = NULL;

- if (tb->ctl) {
- tb_ctl_stop(tb->ctl);
- tb_ctl_free(tb->ctl);
- }
- tb->ctl = NULL;
- tb->hotplug_active = false; /* signal tb_handle_hotplug to quit */
-
- /* allow tb_handle_hotplug to acquire the lock */
- mutex_unlock(&tb->lock);
- if (tb->wq) {
- flush_workqueue(tb->wq);
- destroy_workqueue(tb->wq);
- tb->wq = NULL;
- }
- mutex_destroy(&tb->lock);
- kfree(tb);
+ tcm->hotplug_active = false; /* signal tb_handle_hotplug to quit */
}

-/**
- * thunderbolt_alloc_and_start() - setup the thunderbolt bus
- *
- * Allocates a tb_cfg control channel, initializes the root switch, enables
- * plug events and activates pci devices.
- *
- * Return: Returns NULL on error.
- */
-struct tb *thunderbolt_alloc_and_start(struct tb_nhi *nhi)
+static int tb_start(struct tb *tb)
{
- struct tb *tb;
-
- BUILD_BUG_ON(sizeof(struct tb_regs_switch_header) != 5 * 4);
- BUILD_BUG_ON(sizeof(struct tb_regs_port_header) != 8 * 4);
- BUILD_BUG_ON(sizeof(struct tb_regs_hop) != 2 * 4);
-
- tb = kzalloc(sizeof(*tb), GFP_KERNEL);
- if (!tb)
- return NULL;
-
- tb->nhi = nhi;
- mutex_init(&tb->lock);
- mutex_lock(&tb->lock);
- INIT_LIST_HEAD(&tb->tunnel_list);
-
- tb->wq = alloc_ordered_workqueue("thunderbolt", 0);
- if (!tb->wq)
- goto err_locked;
-
- tb->ctl = tb_ctl_alloc(tb->nhi, tb_schedule_hotplug_handler, tb);
- if (!tb->ctl)
- goto err_locked;
- /*
- * tb_schedule_hotplug_handler may be called as soon as the config
- * channel is started. Thats why we have to hold the lock here.
- */
- tb_ctl_start(tb->ctl);
+ struct tb_cm *tcm = tb_priv(tb);

tb->root_switch = tb_switch_alloc(tb, 0);
if (!tb->root_switch)
- goto err_locked;
+ return -ENOMEM;

/* Full scan to discover devices added before the driver was loaded. */
tb_scan_switch(tb->root_switch);
tb_activate_pcie_devices(tb);

/* Allow tb_handle_hotplug to progress events */
- tb->hotplug_active = true;
- mutex_unlock(&tb->lock);
- return tb;
-
-err_locked:
- mutex_unlock(&tb->lock);
- thunderbolt_shutdown_and_free(tb);
- return NULL;
+ tcm->hotplug_active = true;
+ return 0;
}

-void thunderbolt_suspend(struct tb *tb)
+static int tb_suspend_noirq(struct tb *tb)
{
+ struct tb_cm *tcm = tb_priv(tb);
+
tb_info(tb, "suspending...\n");
- mutex_lock(&tb->lock);
tb_switch_suspend(tb->root_switch);
- tb_ctl_stop(tb->ctl);
- tb->hotplug_active = false; /* signal tb_handle_hotplug to quit */
- mutex_unlock(&tb->lock);
+ tcm->hotplug_active = false; /* signal tb_handle_hotplug to quit */
tb_info(tb, "suspend finished\n");
+
+ return 0;
}

-void thunderbolt_resume(struct tb *tb)
+static int tb_resume_noirq(struct tb *tb)
{
+ struct tb_cm *tcm = tb_priv(tb);
struct tb_pci_tunnel *tunnel, *n;
+
tb_info(tb, "resuming...\n");
- mutex_lock(&tb->lock);
- tb_ctl_start(tb->ctl);

/* remove any pci devices the firmware might have setup */
tb_switch_reset(tb, 0);
@@ -419,9 +375,9 @@ void thunderbolt_resume(struct tb *tb)
tb_switch_resume(tb->root_switch);
tb_free_invalid_tunnels(tb);
tb_free_unplugged_children(tb->root_switch);
- list_for_each_entry_safe(tunnel, n, &tb->tunnel_list, list)
+ list_for_each_entry_safe(tunnel, n, &tcm->tunnel_list, list)
tb_pci_restart(tunnel);
- if (!list_empty(&tb->tunnel_list)) {
+ if (!list_empty(&tcm->tunnel_list)) {
/*
* the pcie links need some time to get going.
* 100ms works for me...
@@ -430,7 +386,33 @@ void thunderbolt_resume(struct tb *tb)
msleep(100);
}
/* Allow tb_handle_hotplug to progress events */
- tb->hotplug_active = true;
- mutex_unlock(&tb->lock);
+ tcm->hotplug_active = true;
tb_info(tb, "resume finished\n");
+
+ return 0;
+}
+
+static const struct tb_cm_ops tb_cm_ops = {
+ .start = tb_start,
+ .stop = tb_stop,
+ .suspend_noirq = tb_suspend_noirq,
+ .resume_noirq = tb_resume_noirq,
+ .hotplug = tb_schedule_hotplug_handler,
+};
+
+struct tb *tb_probe(struct tb_nhi *nhi)
+{
+ struct tb_cm *tcm;
+ struct tb *tb;
+
+ tb = tb_domain_alloc(nhi, sizeof(*tcm));
+ if (!tb)
+ return NULL;
+
+ tb->cm_ops = &tb_cm_ops;
+
+ tcm = tb_priv(tb);
+ INIT_LIST_HEAD(&tcm->tunnel_list);
+
+ return tb;
}
diff --git a/drivers/thunderbolt/tb.h b/drivers/thunderbolt/tb.h
index 9b60e71562dc..ce9db64e3333 100644
--- a/drivers/thunderbolt/tb.h
+++ b/drivers/thunderbolt/tb.h
@@ -92,29 +92,52 @@ struct tb_path {
int path_length; /* number of hops */
};

+/**
+ * struct tb_cm_ops - Connection manager specific operations vector
+ * @start: Starts the domain
+ * @stop: Stops the domain
+ * @suspend_noirq: Connection manager specific suspend_noirq
+ * @resume_noirq: Connection manager specific resume_noirq
+ * @hotplug: Handle hotplug event
+ */
+struct tb_cm_ops {
+ int (*start)(struct tb *tb);
+ void (*stop)(struct tb *tb);
+ int (*suspend_noirq)(struct tb *tb);
+ int (*resume_noirq)(struct tb *tb);
+ hotplug_cb hotplug;
+};

/**
* struct tb - main thunderbolt bus structure
+ * @dev: Domain device
+ * @lock: Big lock. Must be held when accessing cfg or any struct
+ * tb_switch / struct tb_port.
+ * @nhi: Pointer to the NHI structure
+ * @ctl: Control channel for this domain
+ * @wq: Ordered workqueue for all domain specific work
+ * @root_switch: Root switch of this domain
+ * @cm_ops: Connection manager specific operations vector
+ * @index: Linux assigned domain number
+ * @privdata: Private connection manager specific data
*/
struct tb {
- struct mutex lock; /*
- * Big lock. Must be held when accessing cfg or
- * any struct tb_switch / struct tb_port.
- */
+ struct device dev;
+ struct mutex lock;
struct tb_nhi *nhi;
struct tb_ctl *ctl;
- struct workqueue_struct *wq; /* ordered workqueue for plug events */
+ struct workqueue_struct *wq;
struct tb_switch *root_switch;
- struct list_head tunnel_list; /* list of active PCIe tunnels */
- bool hotplug_active; /*
- * tb_handle_hotplug will stop progressing plug
- * events and exit if this is not set (it needs to
- * acquire the lock one more time). Used to drain
- * wq after cfg has been paused.
- */
-
+ const struct tb_cm_ops *cm_ops;
+ int index;
+ unsigned long privdata[0];
};

+static inline void *tb_priv(struct tb *tb)
+{
+ return (void *)tb->privdata;
+}
+
/* helper functions & macros */

/**
@@ -215,11 +238,24 @@ static inline int tb_port_write(struct tb_port *port, const void *buffer,
#define tb_port_info(port, fmt, arg...) \
__TB_PORT_PRINT(tb_info, port, fmt, ##arg)

+struct tb *tb_probe(struct tb_nhi *nhi);
+
+extern struct bus_type tb_bus_type;
+extern struct device_type tb_domain_type;
+
+int tb_domain_init(void);
+void tb_domain_exit(void);

-struct tb *thunderbolt_alloc_and_start(struct tb_nhi *nhi);
-void thunderbolt_shutdown_and_free(struct tb *tb);
-void thunderbolt_suspend(struct tb *tb);
-void thunderbolt_resume(struct tb *tb);
+struct tb *tb_domain_alloc(struct tb_nhi *nhi, size_t privsize);
+int tb_domain_add(struct tb *tb);
+void tb_domain_remove(struct tb *tb);
+int tb_domain_suspend_noirq(struct tb *tb);
+int tb_domain_resume_noirq(struct tb *tb);
+
+static inline void tb_domain_put(struct tb *tb)
+{
+ put_device(&tb->dev);
+}

struct tb_switch *tb_switch_alloc(struct tb *tb, u64 route);
void tb_switch_free(struct tb_switch *sw);
diff --git a/drivers/thunderbolt/tunnel_pci.c b/drivers/thunderbolt/tunnel_pci.c
index f4ce9845e42a..ca4475907d7a 100644
--- a/drivers/thunderbolt/tunnel_pci.c
+++ b/drivers/thunderbolt/tunnel_pci.c
@@ -194,19 +194,13 @@ int tb_pci_restart(struct tb_pci_tunnel *tunnel)
*/
int tb_pci_activate(struct tb_pci_tunnel *tunnel)
{
- int res;
if (tunnel->path_to_up->activated || tunnel->path_to_down->activated) {
tb_tunnel_WARN(tunnel,
"trying to activate an already activated tunnel\n");
return -EINVAL;
}

- res = tb_pci_restart(tunnel);
- if (res)
- return res;
-
- list_add(&tunnel->list, &tunnel->tb->tunnel_list);
- return 0;
+ return tb_pci_restart(tunnel);
}


@@ -227,6 +221,5 @@ void tb_pci_deactivate(struct tb_pci_tunnel *tunnel)
tb_path_deactivate(tunnel->path_to_down);
if (tunnel->path_to_up->activated)
tb_path_deactivate(tunnel->path_to_up);
- list_del_init(&tunnel->list);
}

--
2.11.0