Re: [RESEND PATCH 1/2] i2c: cros-ec-tunnel: Fix usage of cros_ec_cmd_xfer()

[Guenter Roeck]

On Wed, Aug 10, 2016 at 01:37:18PM -0700, Brian Norris wrote:
> cros_ec_cmd_xfer returns success status if the command transport
> completes successfully, but the execution result is incorrectly ignored.
> In many cases, the execution result is assumed to be successful, leading
> to ignored errors and operating on uninitialized data.
> 
> We've recently introduced the cros_ec_cmd_xfer_status() helper to avoid these
> problems. Let's use it.
> 
> [Regarding the 'Fixes' tag; there is significant refactoring since the driver's
> introduction, but the underlying logical error exists throughout I believe]
> 
> Fixes: 9d230c9e4f4e ("i2c: ChromeOS EC tunnel driver")
> Cc: <stable@xxxxxxxxxxxxxxx> # 9798ac6d32c1 mfd: cros_ec: Add cros_ec_cmd_xfer_status() helper
> Signed-off-by: Brian Norris <briannorris@xxxxxxxxxxxx>
> Reviewed-by: Javier Martinez Canillas <javier@xxxxxxxxxxxxxxx>
> Acked-by: Wolfram Sang <wsa@xxxxxxxxxxxxx>

Reviewed-by: Guenter Roeck <linux@xxxxxxxxxxxx>

> ---
>  drivers/i2c/busses/i2c-cros-ec-tunnel.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/i2c/busses/i2c-cros-ec-tunnel.c b/drivers/i2c/busses/i2c-cros-ec-tunnel.c
> index a0d95ff682ae..2d5ff86398d0 100644
> --- a/drivers/i2c/busses/i2c-cros-ec-tunnel.c
> +++ b/drivers/i2c/busses/i2c-cros-ec-tunnel.c
> @@ -215,7 +215,7 @@ static int ec_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg i2c_msgs[],
>  	msg->outsize = request_len;
>  	msg->insize = response_len;
>  
> -	result = cros_ec_cmd_xfer(bus->ec, msg);
> +	result = cros_ec_cmd_xfer_status(bus->ec, msg);
>  	if (result < 0) {
>  		dev_err(dev, "Error transferring EC i2c message %d\n", result);
>  		goto exit;
> -- 
> 2.8.0.rc3.226.g39d4020
>