[PATCH v2] ath10k: implement get_survey()
Kalle Valo
kvalo at qca.qualcomm.com
Wed Jul 31 02:24:30 EDT 2013
Michal Kazior <michal.kazior at tieto.com> writes:
> This implements a limited subset of what can be
> reported in the survey dump.
>
> This can be used for assessing approximate channel
> load, e.g. for automatic channel selection.
>
> Signed-off-by: Michal Kazior <michal.kazior at tieto.com>
[...]
> @@ -374,6 +375,11 @@ struct ath10k {
>
> struct work_struct restart_work;
>
> + /* cycle count is reported twice for each visited channel during scan */
> + u32 survey_last_rx_clear_count;
> + u32 survey_last_cycle_count;
> + struct survey_info survey[ATH10K_NUM_CHANS];
Please document the locking. Apparently survey is protected with
data_lock?
[...]
> static void ath10k_wmi_event_chan_info(struct ath10k *ar, struct sk_buff *skb)
> {
> - ath10k_dbg(ATH10K_DBG_WMI, "WMI_CHAN_INFO_EVENTID\n");
> + struct wmi_chan_info_event *ev;
> + int idx;
> +
> + spin_lock_bh(&ar->data_lock);
> +
> + ev = (struct wmi_chan_info_event *)skb->data;
> + ath10k_dbg(ATH10K_DBG_WMI,
> + "chan info: err_code:%d freq:%d cmd_flags:%d noise_floor:%d rx_clear_count:%d cycle_count:%d\n",
> + __le32_to_cpu(ev->err_code),
> + __le32_to_cpu(ev->freq),
> + __le32_to_cpu(ev->cmd_flags),
> + __le32_to_cpu(ev->noise_floor),
> + __le32_to_cpu(ev->rx_clear_count),
> + __le32_to_cpu(ev->cycle_count));
"wmi event chan info err_code %d freq %d cmd_flags %d noise_floor %d rx_clear_count %d cycle_count %d\n"
> + if (!ar->scan.in_progress) {
> + ath10k_warn("chan info event without a scan request?\n");
> + goto exit;
> + }
> +
> + if (__le32_to_cpu(ev->cmd_flags) & WMI_CHAN_INFO_FLAG_COMPLETE) {
> + idx = freq_to_idx(ar, __le32_to_cpu(ev->freq));
> + if (idx >= ARRAY_SIZE(ar->survey)) {
> + ath10k_warn("chan info: invalid frequency %d (idx %d out of bounds)\n",
> + __le32_to_cpu(ev->freq), idx);
I think we should just bail out if this happens.
> + } else {
> + /* During scanning chan info is reported twice for each
> + * visited channel. The reported cycle count is global
> + * and per-channel cycle count must be calculated */
> +
> + ar->survey[idx].channel_time = WMI_CHAN_INFO_MSEC(
> + __le32_to_cpu(ev->cycle_count) -
> + ar->survey_last_cycle_count);
> + ar->survey[idx].channel_time_rx = WMI_CHAN_INFO_MSEC(
> + __le32_to_cpu(ev->rx_clear_count) -
> + ar->survey_last_rx_clear_count);
> + ar->survey[idx].noise = __le32_to_cpu(ev->noise_floor);
> + ar->survey[idx].filled = SURVEY_INFO_CHANNEL_TIME |
> + SURVEY_INFO_CHANNEL_TIME_RX |
> + SURVEY_INFO_NOISE_DBM;
> + }
...and then there's no reason to use else branch here. Also you can add
temporary variables time and time_rx to make clean up the indentation.
> + }
> +
> + ar->survey_last_rx_clear_count = __le32_to_cpu(ev->rx_clear_count);
> + ar->survey_last_cycle_count = __le32_to_cpu(ev->cycle_count);
> +
> +exit:
> + spin_unlock_bh(&ar->data_lock);
> }
>
> static void ath10k_wmi_event_echo(struct ath10k *ar, struct sk_buff *skb)
> diff --git a/drivers/net/wireless/ath/ath10k/wmi.h b/drivers/net/wireless/ath/ath10k/wmi.h
> index da3b2bc..4acff47 100644
> --- a/drivers/net/wireless/ath/ath10k/wmi.h
> +++ b/drivers/net/wireless/ath/ath10k/wmi.h
> @@ -2931,6 +2931,9 @@ struct wmi_chan_info_event {
> __le32 cycle_count;
> } __packed;
>
> +#define WMI_CHAN_INFO_FLAG_COMPLETE BIT(0)
> +#define WMI_CHAN_INFO_MSEC(x) ((x) / 76595) /* XXX: empirically extrapolated */
Use "FIXME:" and comment on a separate line:
/* FIXME: empirically extrapolated */
#define WMI_CHAN_INFO_MSEC(x) ((x) / 76595)
--
Kalle Valo
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