FAILED: patch "[PATCH] thunderbolt: Initialize HopID IDAs in tb_switch_alloc()" failed to apply to 5.4-stable tree

[<gregkh@linuxfoundation.org>]

The patch below does not apply to the 5.4-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@vger.kernel.org>.

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 781e14eaa7d168dc07d2a2eea5c55831a5bb46f3 Mon Sep 17 00:00:00 2001
From: Mika Westerberg <mika.westerberg@linux.intel.com>
Date: Wed, 10 Feb 2021 16:06:33 +0200
Subject: [PATCH] thunderbolt: Initialize HopID IDAs in tb_switch_alloc()

If there is a failure before the tb_switch_add() is called the switch
object is released by tb_switch_release() but at that point HopID IDAs
have not yet been initialized. So we see splat like this:

BUG: spinlock bad magic on CPU#2, kworker/u8:5/115
...
Workqueue: thunderbolt0 tb_handle_hotplug
Call Trace:
 dump_stack+0x97/0xdc
 ? spin_bug+0x9a/0xa7
 do_raw_spin_lock+0x68/0x98
 _raw_spin_lock_irqsave+0x3f/0x5d
 ida_destroy+0x4f/0x127
 tb_switch_release+0x6d/0xfd
 device_release+0x2c/0x7d
 kobject_put+0x9b/0xbc
 tb_handle_hotplug+0x278/0x452
 process_one_work+0x1db/0x396
 worker_thread+0x216/0x375
 kthread+0x14d/0x155
 ? pr_cont_work+0x58/0x58
 ? kthread_blkcg+0x2e/0x2e
 ret_from_fork+0x1f/0x40

Fix this by always initializing HopID IDAs in tb_switch_alloc().

Fixes: 0b2863ac3cfd ("thunderbolt: Add functions for allocating and releasing HopIDs")
Cc: stable@vger.kernel.org
Reported-by: Chiranjeevi Rapolu <chiranjeevi.rapolu@intel.com>
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>

diff --git a/drivers/thunderbolt/switch.c b/drivers/thunderbolt/switch.c
index b63fecca6c2a..2a95b4ce06c0 100644
--- a/drivers/thunderbolt/switch.c
+++ b/drivers/thunderbolt/switch.c
@@ -768,12 +768,6 @@ static int tb_init_port(struct tb_port *port)
 
 	tb_dump_port(port->sw->tb, &port->config);
 
-	/* Control port does not need HopID allocation */
-	if (port->port) {
-		ida_init(&port->in_hopids);
-		ida_init(&port->out_hopids);
-	}
-
 	INIT_LIST_HEAD(&port->list);
 	return 0;
 
@@ -1842,10 +1836,8 @@ static void tb_switch_release(struct device *dev)
 	dma_port_free(sw->dma_port);
 
 	tb_switch_for_each_port(sw, port) {
-		if (!port->disabled) {
-			ida_destroy(&port->in_hopids);
-			ida_destroy(&port->out_hopids);
-		}
+		ida_destroy(&port->in_hopids);
+		ida_destroy(&port->out_hopids);
 	}
 
 	kfree(sw->uuid);
@@ -2025,6 +2017,12 @@ struct tb_switch *tb_switch_alloc(struct tb *tb, struct device *parent,
 		/* minimum setup for tb_find_cap and tb_drom_read to work */
 		sw->ports[i].sw = sw;
 		sw->ports[i].port = i;
+
+		/* Control port does not need HopID allocation */
+		if (i) {
+			ida_init(&sw->ports[i].in_hopids);
+			ida_init(&sw->ports[i].out_hopids);
+		}
 	}
 
 	ret = tb_switch_find_vse_cap(sw, TB_VSE_CAP_PLUG_EVENTS);