Re: [PATCH] Bluetooth: btusb: CSR chip hangs when unbound

[Greg KH <gregkh@linuxfoundation.org>]

On Fri, Apr 29, 2022 at 05:31:38PM +0200, Jose Ignacio Tornos Martinez wrote:
> Bluetooth Dongles with CSR chip (i.e. USB Bluetooth V4.0 Dongle by
> Trust) hang when they are unbound from 'unbind' sysfs entry and
> can not be bound again.
> 
> The reason is CSR chip hangs when usb configuration command with
> index 0 (used to unconfigure) is sent during disconnection.
> 
> To avoid this unwanted result, it is necessary not to send this
> command for CSR chip when usb device is unbound.
> Besides, "skip_unconfigure" sysfs entry has been created for
> testing purposes with these or other devices.
> 
> Athough device is not unconfigured, it is better to avoid device
> hanging to be able to operate. Even bluetooth can be previously
> turned off.
> On the other hand, this is not important if usb device is going to
> be bound again (normal behavior), i.e. with usbip.
> 
> Signed-off-by: Jose Ignacio Tornos Martinez <jtornosm@redhat.com>
> ---
>  drivers/bluetooth/btusb.c  |  8 +++++++-
>  drivers/usb/core/generic.c |  2 +-
>  drivers/usb/core/sysfs.c   | 36 ++++++++++++++++++++++++++++++++++++
>  include/linux/usb.h        |  2 ++
>  4 files changed, 46 insertions(+), 2 deletions(-)

No documentation for this new sysfs attribute you wish to create?
That's not going to help us with review :(

thanks,

greg k-h