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Subject: Re: [PATCH] staging: pi433: add descriptions for mutex locks
To:     Valentin Vidic <Valentin.Vidic@CARNet.hr>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc:     =?UTF-8?Q?Simon_Sandstr=c3=b6m?= <simon@nikanor.nu>,
        Marcus Wolf <linux@Wolf-Entwicklungen.de>,
        =?UTF-8?Q?Luca_S=c3=b6the?= <luca@acul.me>,
        Marcin Ciupak <marcin.s.ciupak@gmail.com>,
        Michael Panzlaff <michael.panzlaff@fau.de>,
        Derek Robson <robsonde@gmail.com>, devel@driverdev.osuosl.org,
        linux-kernel@vger.kernel.org
References: <20180323094725.4904-1-Valentin.Vidic@CARNet.hr>
From:   Marcus Wolf <marcus.wolf@smarthome-wolf.de>
Message-ID: <d263c605-f652-fe24-2034-c699f2d27693@smarthome-wolf.de>
Date:   Fri, 23 Mar 2018 11:22:39 +0100
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Hi Valentin,

could you please decribe in short words, why you think, that hte lock
isn't obsolete?

I wasn't sure, but close to remove the lock. That's why I putted the
comment.

Thanks,

Marcus

Am 23.03.2018 um 10:47 schrieb Valentin Vidic:
> Removes TODO for tx_fifo_lock as tx_fifo is modified from
> both pi433_tx_thread and pi433_write.
> 
> Fixes checkpatch warning:
> 
>   CHECK: struct mutex definition without comment
> 
> Signed-off-by: Valentin Vidic <Valentin.Vidic@CARNet.hr>
> ---
>  drivers/staging/pi433/pi433_if.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/staging/pi433/pi433_if.c b/drivers/staging/pi433/pi433_if.c
> index d1e0ddbc79ce..f6f106a3ff8e 100644
> --- a/drivers/staging/pi433/pi433_if.c
> +++ b/drivers/staging/pi433/pi433_if.c
> @@ -87,7 +87,7 @@ struct pi433_device {
>  
>  	/* tx related values */
>  	STRUCT_KFIFO_REC_1(MSG_FIFO_SIZE) tx_fifo;
> -	struct mutex		tx_fifo_lock; // TODO: check, whether necessary or obsolete
> +	struct mutex		tx_fifo_lock; /* serialize access to tx_fifo */
>  	struct task_struct	*tx_task_struct;
>  	wait_queue_head_t	tx_wait_queue;
>  	u8			free_in_fifo;
> @@ -100,7 +100,7 @@ struct pi433_device {
>  	u32			rx_bytes_to_drop;
>  	u32			rx_bytes_dropped;
>  	unsigned int		rx_position;
> -	struct mutex		rx_lock;
> +	struct mutex		rx_lock; /* serialize read requests */
>  	wait_queue_head_t	rx_wait_queue;
>  
>  	/* fifo wait queue */
> 

-- 
Smarthome-Wolf UG (haftungsbeschränkt)
Helene-Lange-Weg 23
80637 München
Amtsgericht München, HRB 223529
Umastzsteuer-ID: DE304719911
Geschäftsführer: Marcus Wolf