Re: [char-misc-next 4/5] mei: nfc: clean nfc internal struct on host exit

[Greg KH <gregkh@linuxfoundation.org>]

On Thu, Jul 17, 2014 at 10:53:37AM +0300, Tomas Winkler wrote:
> From: Alexander Usyskin <alexander.usyskin@intel.com>
> 
> NFC internal structure cleaning was dropped by commit
> 
> commit 5ad1550a15cd5b75ed8aa3009e162822f720375e
> Author: Tomas Winkler <tomas.winkler@intel.com>
> Date:   Sun Jan 26 11:53:06 2014 +0200
> 
>     mei: Remove all bus devices from the mei_dev list when stopping the MEI
> 
> Bring back cleaning of structure only, because it broke
> host init after host exit scenario (like after S3):
> mei_nfc_host_init checks ndev->cl_info and does nothing if it's dirty.
> 
> Cc: stable@vger.kernel.org # 3.15+
> Signed-off-by: Alexander Usyskin <alexander.usyskin@intel.com>
> Signed-off-by: Tomas Winkler <tomas.winkler@intel.com>
> ---
>  drivers/misc/mei/nfc.c | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/drivers/misc/mei/nfc.c b/drivers/misc/mei/nfc.c
> index 3095fc5..257f01f 100644
> --- a/drivers/misc/mei/nfc.c
> +++ b/drivers/misc/mei/nfc.c
> @@ -553,6 +553,7 @@ void mei_nfc_host_exit(struct mei_device *dev)
>  {
>  	struct mei_nfc_dev *ndev = &nfc_dev;
>  	cancel_work_sync(&ndev->init_work);
> +	memset(ndev, 0, sizeof(struct mei_nfc_dev));

This implies that something is using a "static" device structure, which
isn't allowed by the driver core.  So please fix the root cause here,
don't paper over the bug.

thanks,

greg k-h