thunderbolt: Decrease control channel timeout for software connection manager

When the firmware connection manager is not proxying between the
software and the hardware we can decrease the timeout for control
packets significantly. The USB4 spec recommends 10 ms +- 1 ms but we use
slightly larger value (100 ms) which is recommendation from Intel
Thunderbolt firmware folks. When firmware connection manager is running
then we keep using the existing 5000 ms.

To implement this we move the control channel allocation to
tb_domain_alloc(), and pass the timeout from that function to the
tb_ctl_alloc(). Then make both connection manager implementations pass
the timeout when they alloc the domain structure.

While there update kernel-doc of struct tb_ctl to match the reality.
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>

drivers/thunderbolt/ctl.c

@@ -29,6 +29,7 @@
  * @request_queue_lock: Lock protecting @request_queue
  * @request_queue: List of outstanding requests
  * @running: Is the control channel running at the moment
+ * @timeout_msec: Default timeout for non-raw control messages
  * @callback: Callback called when hotplug message is received
  * @callback_data: Data passed to @callback
  */
@@ -43,6 +44,7 @@ struct tb_ctl {
 	struct list_head request_queue;
 	bool running;
 
+	int timeout_msec;
 	event_cb callback;
 	void *callback_data;
 };
@@ -613,6 +615,7 @@ struct tb_cfg_result tb_cfg_request_sync(struct tb_ctl *ctl,
 /**
  * tb_ctl_alloc() - allocate a control channel
  * @nhi: Pointer to NHI
+ * @timeout_msec: Default timeout used with non-raw control messages
  * @cb: Callback called for plug events
  * @cb_data: Data passed to @cb
  *
@@ -620,13 +623,15 @@ struct tb_cfg_result tb_cfg_request_sync(struct tb_ctl *ctl,
  *
  * Return: Returns a pointer on success or NULL on failure.
  */
-struct tb_ctl *tb_ctl_alloc(struct tb_nhi *nhi, event_cb cb, void *cb_data)
+struct tb_ctl *tb_ctl_alloc(struct tb_nhi *nhi, int timeout_msec, event_cb cb,
+			    void *cb_data)
 {
 	int i;
 	struct tb_ctl *ctl = kzalloc(sizeof(*ctl), GFP_KERNEL);
 	if (!ctl)
 		return NULL;
 	ctl->nhi = nhi;
+	ctl->timeout_msec = timeout_msec;
 	ctl->callback = cb;
 	ctl->callback_data = cb_data;
 
@@ -829,7 +834,7 @@ struct tb_cfg_result tb_cfg_reset(struct tb_ctl *ctl, u64 route)
 	req->response_size = sizeof(reply);
 	req->response_type = TB_CFG_PKG_RESET;
 
-	res = tb_cfg_request_sync(ctl, req, TB_CFG_DEFAULT_TIMEOUT);
+	res = tb_cfg_request_sync(ctl, req, ctl->timeout_msec);
 
 	tb_cfg_request_put(req);
 
@@ -1005,7 +1010,7 @@ int tb_cfg_read(struct tb_ctl *ctl, void *buffer, u64 route, u32 port,
 		enum tb_cfg_space space, u32 offset, u32 length)
 {
 	struct tb_cfg_result res = tb_cfg_read_raw(ctl, buffer, route, port,
-			space, offset, length, TB_CFG_DEFAULT_TIMEOUT);
+			space, offset, length, ctl->timeout_msec);
 	switch (res.err) {
 	case 0:
 		/* Success */
@@ -1031,7 +1036,7 @@ int tb_cfg_write(struct tb_ctl *ctl, const void *buffer, u64 route, u32 port,
 		 enum tb_cfg_space space, u32 offset, u32 length)
 {
 	struct tb_cfg_result res = tb_cfg_write_raw(ctl, buffer, route, port,
-			space, offset, length, TB_CFG_DEFAULT_TIMEOUT);
+			space, offset, length, ctl->timeout_msec);
 	switch (res.err) {
 	case 0:
 		/* Success */
@@ -1069,7 +1074,7 @@ int tb_cfg_get_upstream_port(struct tb_ctl *ctl, u64 route)
 	u32 dummy;
 	struct tb_cfg_result res = tb_cfg_read_raw(ctl, &dummy, route, 0,
 						   TB_CFG_SWITCH, 0, 1,
-						   TB_CFG_DEFAULT_TIMEOUT);
+						   ctl->timeout_msec);
 	if (res.err == 1)
 		return -EIO;
 	if (res.err)

drivers/thunderbolt/ctl.h

@@ -21,15 +21,14 @@ struct tb_ctl;
 typedef bool (*event_cb)(void *data, enum tb_cfg_pkg_type type,
 			 const void *buf, size_t size);
 
-struct tb_ctl *tb_ctl_alloc(struct tb_nhi *nhi, event_cb cb, void *cb_data);
+struct tb_ctl *tb_ctl_alloc(struct tb_nhi *nhi, int timeout_msec, event_cb cb,
+			    void *cb_data);
 void tb_ctl_start(struct tb_ctl *ctl);
 void tb_ctl_stop(struct tb_ctl *ctl);
 void tb_ctl_free(struct tb_ctl *ctl);
 
 /* configuration commands */
 
-#define TB_CFG_DEFAULT_TIMEOUT 5000 /* msec */
-
 struct tb_cfg_result {
 	u64 response_route;
 	u32 response_port; /*

drivers/thunderbolt/domain.c

@@ -341,9 +341,34 @@ struct device_type tb_domain_type = {
 	.release = tb_domain_release,
 };
 
+static bool tb_domain_event_cb(void *data, enum tb_cfg_pkg_type type,
+			       const void *buf, size_t size)
+{
+	struct tb *tb = data;
+
+	if (!tb->cm_ops->handle_event) {
+		tb_warn(tb, "domain does not have event handler\n");
+		return true;
+	}
+
+	switch (type) {
+	case TB_CFG_PKG_XDOMAIN_REQ:
+	case TB_CFG_PKG_XDOMAIN_RESP:
+		if (tb_is_xdomain_enabled())
+			return tb_xdomain_handle_request(tb, type, buf, size);
+		break;
+
+	default:
+		tb->cm_ops->handle_event(tb, type, buf, size);
+	}
+
+	return true;
+}
+
 /**
  * tb_domain_alloc() - Allocate a domain
  * @nhi: Pointer to the host controller
+ * @timeout_msec: Control channel timeout for non-raw messages
  * @privsize: Size of the connection manager private data
  *
  * Allocates and initializes a new Thunderbolt domain. Connection
@@ -355,7 +380,7 @@ struct device_type tb_domain_type = {
  *
  * 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_domain_alloc(struct tb_nhi *nhi, int timeout_msec, size_t privsize)
 {
 	struct tb *tb;
 
@@ -382,6 +407,10 @@ struct tb *tb_domain_alloc(struct tb_nhi *nhi, size_t privsize)
 	if (!tb->wq)
 		goto err_remove_ida;
 
+	tb->ctl = tb_ctl_alloc(nhi, timeout_msec, tb_domain_event_cb, tb);
+	if (!tb->ctl)
+		goto err_destroy_wq;
+
 	tb->dev.parent = &nhi->pdev->dev;
 	tb->dev.bus = &tb_bus_type;
 	tb->dev.type = &tb_domain_type;
@@ -391,6 +420,8 @@ struct tb *tb_domain_alloc(struct tb_nhi *nhi, size_t privsize)
 
 	return tb;
 
+err_destroy_wq:
+	destroy_workqueue(tb->wq);
 err_remove_ida:
 	ida_simple_remove(&tb_domain_ida, tb->index);
 err_free:
@@ -399,30 +430,6 @@ struct tb *tb_domain_alloc(struct tb_nhi *nhi, size_t privsize)
 	return NULL;
 }
 
-static bool tb_domain_event_cb(void *data, enum tb_cfg_pkg_type type,
-			       const void *buf, size_t size)
-{
-	struct tb *tb = data;
-
-	if (!tb->cm_ops->handle_event) {
-		tb_warn(tb, "domain does not have event handler\n");
-		return true;
-	}
-
-	switch (type) {
-	case TB_CFG_PKG_XDOMAIN_REQ:
-	case TB_CFG_PKG_XDOMAIN_RESP:
-		if (tb_is_xdomain_enabled())
-			return tb_xdomain_handle_request(tb, type, buf, size);
-		break;
-
-	default:
-		tb->cm_ops->handle_event(tb, type, buf, size);
-	}
-
-	return true;
-}
-
 /**
  * tb_domain_add() - Add domain to the system
  * @tb: Domain to add
@@ -442,13 +449,6 @@ int tb_domain_add(struct tb *tb)
 		return -EINVAL;
 
 	mutex_lock(&tb->lock);
-
-	tb->ctl = tb_ctl_alloc(tb->nhi, tb_domain_event_cb, 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.
@@ -493,8 +493,6 @@ int tb_domain_add(struct tb *tb)
 	device_del(&tb->dev);
 err_ctl_stop:
 	tb_ctl_stop(tb->ctl);
-err_unlock:
-	mutex_unlock(&tb->lock);
 
 	return ret;
 }

drivers/thunderbolt/icm.c

@@ -2416,7 +2416,7 @@ struct tb *icm_probe(struct tb_nhi *nhi)
 	struct icm *icm;
 	struct tb *tb;
 
-	tb = tb_domain_alloc(nhi, sizeof(struct icm));
+	tb = tb_domain_alloc(nhi, ICM_TIMEOUT, sizeof(struct icm));
 	if (!tb)
 		return NULL;
 

drivers/thunderbolt/tb.c

@@ -15,6 +15,8 @@
 #include "tb_regs.h"
 #include "tunnel.h"
 
+#define TB_TIMEOUT	100 /* ms */
+
 /**
  * struct tb_cm - Simple Thunderbolt connection manager
  * @tunnel_list: List of active tunnels
@@ -1558,7 +1560,7 @@ struct tb *tb_probe(struct tb_nhi *nhi)
 	struct tb_cm *tcm;
 	struct tb *tb;
 
-	tb = tb_domain_alloc(nhi, sizeof(*tcm));
+	tb = tb_domain_alloc(nhi, TB_TIMEOUT, sizeof(*tcm));
 	if (!tb)
 		return NULL;
 

drivers/thunderbolt/tb.h

@@ -625,7 +625,7 @@ void tb_domain_exit(void);
 int tb_xdomain_init(void);
 void tb_xdomain_exit(void);
 
-struct tb *tb_domain_alloc(struct tb_nhi *nhi, size_t privsize);
+struct tb *tb_domain_alloc(struct tb_nhi *nhi, int timeout_msec, 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);