commit e852c2c251ed9c23ae6e3efebc5ec49adb504207 upstream.
It's not needed to set driver to NULL in mei_cl_device_remove()
which is bus_type remove() handler as this is done anyway
in __device_release_driver().
Actually this is causing an endless loop in driver_detach()
on ubuntu patched kernel, while removing (rmmod) the mei_hdcp module.
The reason list_empty(&drv->p->klist_devices.k_list) is always not-empty.
as the check is always true in __device_release_driver()
if (dev->driver != drv)
return;
The non upstream patch is causing this behavior, titled:
'vfio -- release device lock before userspace requests'
Nevertheless the fix is correct also for the upstream.
Link: https://patchwork.ozlabs.org/project/ubuntu-kernel/patch/20180912085046.3401-2-apw@canonical.com/
Cc: <stable@vger.kernel.org>
Cc: Andy Whitcroft <apw@canonical.com>
Signed-off-by: Alexander Usyskin <alexander.usyskin@intel.com>
Signed-off-by: Tomas Winkler <tomas.winkler@intel.com>
Link: https://lore.kernel.org/r/20200628225359.2185929-1-tomas.winkler@intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
abc43bec3f