Re: [PATCH 2/2] mac80211: Add support for aborting an ongoing scan

[Johannes Berg <johannes@sipsolutions.net>]

On Thu, 2015-10-29 at 13:16 +0530, Sunil Dutt wrote:
> From: Vidyullatha Kanchanapally <vkanchan@qti.qualcomm.com>
> 
> This commit adds implementation for abort scan in mac80211.
> 
> Reviewed-by: Jouni Malinen <jouni@qca.qualcomm.com>
> Signed-off-by: Vidyullatha Kanchanapally <vkanchan@qti.qualcomm.com>
> Signed-off-by: Sunil Dutt <usdutt@qti.qualcomm.com>
> ---
>  net/mac80211/cfg.c | 11 +++++++++++
>  1 file changed, 11 insertions(+)
> 
> diff --git a/net/mac80211/cfg.c b/net/mac80211/cfg.c
> index 713cdbf..d4d78e1 100644
> --- a/net/mac80211/cfg.c
> +++ b/net/mac80211/cfg.c
> @@ -3797,6 +3797,16 @@ static int ieee80211_del_tx_ts(struct wiphy 
> *wiphy, struct net_device *dev,
>  	return -ENOENT;
>  }
>  
> +static int ieee80211_abort_scan(struct wiphy *wiphy, struct 
> net_device *dev)
> +{
> +	struct ieee80211_sub_if_data *sdata = 
> IEEE80211_DEV_TO_SUB_IF(dev);
> +	struct ieee80211_local *local = sdata->local;
> +
> +	/* Cancel the ongoing scan */
> +	ieee80211_scan_cancel(local);
> +	return 0;
> +}

You're not returning -ENOENT when there's no scan, which could be racy?
I'm not sure those races would be relevant, but you should think about
that and document it.

johannes