FAILED: patch "[PATCH] Bluetooth: hci_bcm: fix freeing not-requested IRQ" failed to apply to 4.4-stable tree

The patch below does not apply to the 4.4-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 <[email protected]>.

thanks,

greg k-h

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

From 81bd5d0c62437c02caac6b3f942fcda874063cb0 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Micha=C5=82=20Miros=C5=82aw?= <[email protected]>
Date: Thu, 2 Apr 2020 14:55:20 +0200
Subject: [PATCH] Bluetooth: hci_bcm: fix freeing not-requested IRQ
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When BT module can't be initialized, but it has an IRQ, unloading the driver WARNs when trying to free not-yet-requested IRQ. Fix it by noting whether the IRQ was requested.

WARNING: CPU: 2 PID: 214 at kernel/irq/devres.c:144 devm_free_irq+0x49/0x4ca
[...]
WARNING: CPU: 2 PID: 214 at kernel/irq/manage.c:1746 __free_irq+0x8b/0x27c
Trying to free already-free IRQ 264
Modules linked in: hci_uart(-) btbcm bluetooth ecdh_generic ecc libaes
CPU: 2 PID: 214 Comm: rmmod Tainted: G        W         5.6.1mq-00044-ga5f9ea098318-dirty #928

[...]
[<b016aefb>] (devm_free_irq) from [<af8ba1ff>] (bcm_close+0x97/0x118 [hci_uart]) [<af8ba1ff>] (bcm_close [hci_uart]) from [<af8b736f>] (hci_uart_unregister_device+0x33/0x3c [hci_uart]) [<af8b736f>] (hci_uart_unregister_device [hci_uart]) from [<b035930b>] (serdev_drv_remove+0x13/0x20) [<b035930b>] (serdev_drv_remove) from [<b037093b>] (device_release_driver_internal+0x97/0x118) [<b037093b>] (device_release_driver_internal) from [<b0370a0b>] (driver_detach+0x2f/0x58) [<b0370a0b>] (driver_detach) from [<b036f855>] (bus_remove_driver+0x41/0x94) [<b036f855>] (bus_remove_driver) from [<af8ba8db>] (bcm_deinit+0x1b/0x740 [hci_uart]) [<af8ba8db>] (bcm_deinit [hci_uart]) from [<af8ba86f>] (hci_uart_exit+0x13/0x30 [hci_uart]) [<af8ba86f>] (hci_uart_exit [hci_uart]) from [<b01900bd>] (sys_delete_module+0x109/0x1d0) [<b01900bd>] (sys_delete_module) from [<b0101001>] (ret_fast_syscall+0x1/0x5a)
[...]

index 36b7f0d00c4b..19e4587f366c 100644
@@ -118,6 +118,7 @@ struct bcm_device {
 	u32			oper_speed;
 	int			irq;
 	bool			irq_active_low;
+	bool			irq_acquired;
 
 #ifdef CONFIG_PM
 	struct hci_uart		*hu;

@@ -333,6 +334,8 @@ static int bcm_request_irq(struct bcm_data *bcm)
 		goto unlock;
 	}
 
+	bdev->irq_acquired = true;
+
 	device_init_wakeup(bdev->dev, true);
 
 	pm_runtime_set_autosuspend_delay(bdev->dev,

@@ -514,7 +517,7 @@ static int bcm_close(struct hci_uart *hu)
 	}
 
 	if (bdev) {
-		if (IS_ENABLED(CONFIG_PM) && bdev->irq > 0) {
+		if (IS_ENABLED(CONFIG_PM) && bdev->irq_acquired) {
 			devm_free_irq(bdev->dev, bdev->irq, bdev);
 			device_init_wakeup(bdev->dev, false);
 			pm_runtime_disable(bdev->dev);