Received-SPF: pass (google.com: domain of linux-kernel+bounces-5112-linux.lists.archive=gmail.com@vger.kernel.org designates 147.75.199.223 as permitted sender) client-ip=147.75.199.223;
Date: Tue, 19 Dec 2023 13:51:58 +0200
From: Heikki Krogerus <heikki.krogerus@linux.intel.com>
To: Javier Carrasco <javier.carrasco@wolfvision.net>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH v2 3/4] usb: typec: tipd: declare in_data in as const in
 exec_cmd functions
Message-ID: <ZYGD3h1/il9hmdL0@kuha.fi.intel.com>
References: <20231207-tps6598x_update-v2-0-f3cfcde6d890@wolfvision.net>
 <20231207-tps6598x_update-v2-3-f3cfcde6d890@wolfvision.net>
Precedence: bulk
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <20231207-tps6598x_update-v2-3-f3cfcde6d890@wolfvision.net>

On Thu, Dec 14, 2023 at 05:29:11PM +0100, Javier Carrasco wrote:
> The input data passed to execute commands with tps6598x_exec_cmd()
> is not supposed to be modified by the function. Moreover, this data is
> passed to tps6598x_exec_cmd_tmo() and finally to tps6598x_block_write(),
> which expects a const pointer.
> 
> The current implementation does not produce any bugs, but it discards
> const qualifiers from the pointers passed as arguments. This leads to
> compile issues if 'discarded-qualifiers' is active and a const pointer
> is passed to the function, which is the case if data from a firmware
> structure is passed to execute update commands. Adding the const
> modifier to in_data prevents such issues and provides code consistency.
> 
> Signed-off-by: Javier Carrasco <javier.carrasco@wolfvision.net>

Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>

> ---
>  drivers/usb/typec/tipd/core.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/usb/typec/tipd/core.c b/drivers/usb/typec/tipd/core.c
> index 83e5eeecdf5c..7f4bbc0629b0 100644
> --- a/drivers/usb/typec/tipd/core.c
> +++ b/drivers/usb/typec/tipd/core.c
> @@ -330,7 +330,7 @@ static void tps6598x_disconnect(struct tps6598x *tps, u32 status)
>  }
>  
>  static int tps6598x_exec_cmd_tmo(struct tps6598x *tps, const char *cmd,
> -			     size_t in_len, u8 *in_data,
> +			     size_t in_len, const u8 *in_data,
>  			     size_t out_len, u8 *out_data,
>  			     u32 cmd_timeout_ms, u32 res_delay_ms)
>  {
> @@ -396,7 +396,7 @@ static int tps6598x_exec_cmd_tmo(struct tps6598x *tps, const char *cmd,
>  }
>  
>  static int tps6598x_exec_cmd(struct tps6598x *tps, const char *cmd,
> -			     size_t in_len, u8 *in_data,
> +			     size_t in_len, const u8 *in_data,
>  			     size_t out_len, u8 *out_data)
>  {
>  	return tps6598x_exec_cmd_tmo(tps, cmd, in_len, in_data,
> 
> -- 
> 2.39.2

-- 
heikki