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Subject: Re: [PATCH 5.12 regression fix] Bluetooth: btusb: Revert Fix the
 autosuspend enable and disable
To:     Hans de Goede <hdegoede@redhat.com>,
        Marcel Holtmann <marcel@holtmann.org>,
        Johan Hedberg <johan.hedberg@gmail.com>
Cc:     linux-bluetooth@vger.kernel.org
References: <20210218123728.17067-1-hdegoede@redhat.com>
 <20210218123728.17067-2-hdegoede@redhat.com>
From:   Hui Wang <hui.wang@canonical.com>
Message-ID: <90d8996d-a376-2e9c-37ce-ce50b8660fd1@canonical.com>
Date:   Thu, 18 Feb 2021 22:36:07 +0800
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On 2/18/21 8:37 PM, Hans de Goede wrote:
> drivers/usb/core/hub.c: usb_new_device() contains the following:
[...]
>   
>   	err = hci_register_dev(hdev);
>   	if (err < 0)
> @@ -4688,9 +4688,6 @@ static void btusb_disconnect(struct usb_interface *intf)
>   		gpiod_put(data->reset_gpio);
>   
>   	hci_free_dev(hdev);
> -
> -	if (!enable_autosuspend)
> -		usb_enable_autosuspend(data->udev);
Hi Hans,

And Do we need to call usb_disable_autosuspend() in the disconnect()? 
like below:

diff --git a/drivers/bluetooth/btusb.c b/drivers/bluetooth/btusb.c
index 32161dd40ed6..ef831492363c 100644
--- a/drivers/bluetooth/btusb.c
+++ b/drivers/bluetooth/btusb.c
@@ -4673,6 +4673,9 @@ static void btusb_disconnect(struct usb_interface 
*intf)

         hci_unregister_dev(hdev);

+       if (enable_autosuspend)
+               usb_disable_autosuspend(data->udev);
+
         if (intf == data->intf) {
                 if (data->isoc)
usb_driver_release_interface(&btusb_driver, data->isoc);


Before the btusb_probe() is called, the usb device is autosuspend 
disabled, suppose users set the btusb.enable_autosuspend=1, the driver 
btusb will enable the autosuspend on this device. If users remove this 
driver, the disconnect() will be called, the usb device will keep 
autosuspend enabled. Next time if users reload this driver by 'sudo 
modprobe  btusb enalbe_autosuspend=0',  they will find the device is 
autosuspend enabled instead of disabled.

Thanks.


>   }
>   
>   #ifdef CONFIG_PM