| From | Greg Kroah-Hartman <> | Subject | [PATCH 4.14 109/125] mei: bus: dont clean driver pointer | Date | Mon, 20 Jul 2020 17:37:28 +0200 |
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From: Alexander Usyskin <alexander.usyskin@intel.com>
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>
--- drivers/misc/mei/bus.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-)
--- a/drivers/misc/mei/bus.c +++ b/drivers/misc/mei/bus.c @@ -722,9 +722,8 @@ static int mei_cl_device_remove(struct d mei_cldev_unregister_callbacks(cldev); module_put(THIS_MODULE); - dev->driver = NULL; - return ret; + return ret; } static ssize_t name_show(struct device *dev, struct device_attribute *a,
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