[PATCH] ath10k: don't allow stand alone monitor mode for non-AP firmware

[Kalle Valo]

Chun-Yeow Yeoh <yeohchunyeow at gmail.com> writes:

> Firmware 999.999.0.636 does not allow stand alone monitor
> mode. This means that bridging the STA mode and put it into
> promiscuous mode will also cause the firmware to crash. Avoid
> this.
>
> Signed-off-by: Chun-Yeow Yeoh <yeohchunyeow at gmail.com>

[...]

> @@ -647,10 +647,15 @@ static int ath10k_monitor_vdev_delete(struct ath10k *ar)
>  
>  static int ath10k_monitor_start(struct ath10k *ar)
>  {
> -	int ret;
> +	int ret = -1;

I prefer to avoid initialising ret variables. And -1 is not a proper
error value.

>  	lockdep_assert_held(&ar->conf_mutex);
>  
> +	if (ar->fw_version_build == 636) {

Checking for firmware version in ath10k is a big no. For a functinality
change like this you should add a new feature flag to enum
ath10k_fw_features (and I need to then recreate the firmware image).

> +		ath10k_warn("stand alone monitor mode is not supported\n");

I would prefer not to print a warning for a situation like this. Can't
we instead return an error value back to the caller?

> +		return ret;

return -EOPNOTSUPP or similar is better approach than initialising ret
to -1.

-- 
Kalle Valo