Re: [char-misc-next 4/4 V2] mei: bus: enable non-blocking RX

[Greg Kroah-Hartman]

On Sat, Nov 19, 2016 at 02:16:11PM +0200, Tomas Winkler wrote:
> From: Alexander Usyskin <alexander.usyskin@xxxxxxxxx>
> 
> Enable non-blocking receive for drivers on mei bus, this allows checking
> for data availability by mei client drivers. This is most effective for
> fixed address clients, that lacks flow control.
> 
> This function adds new API function mei_cldev_recv_nonblock(), it
> retuns -EGAIN if function will block.
> 
> Signed-off-by: Alexander Usyskin <alexander.usyskin@xxxxxxxxx>
> Signed-off-by: Tomas Winkler <tomas.winkler@xxxxxxxxx>
> ---
> V2: use _nonblock() function suffix instead of NONBLOCK flag
> 
>  drivers/misc/mei/bus-fixup.c |  4 ++--
>  drivers/misc/mei/bus.c       | 31 +++++++++++++++++++++++++++++--
>  drivers/misc/mei/mei_dev.h   |  7 ++++++-
>  include/linux/mei_cl_bus.h   |  6 ++++--
>  4 files changed, 41 insertions(+), 7 deletions(-)
> 
> diff --git a/drivers/misc/mei/bus-fixup.c b/drivers/misc/mei/bus-fixup.c
> index 7f2cef9011ae..18e05ca7584f 100644
> --- a/drivers/misc/mei/bus-fixup.c
> +++ b/drivers/misc/mei/bus-fixup.c
> @@ -141,7 +141,7 @@ static int mei_osver(struct mei_cl_device *cldev)
>  	if (ret < 0)
>  		return ret;
>  
> -	ret = __mei_cl_recv(cldev->cl, buf, length);
> +	ret = __mei_cl_recv(cldev->cl, buf, length, 0);

What is 0 here?  Again, mode...