Subject: Re: [PATCH] ath10k : Fix channel survey dump
To: Venkateswara Rao Naralasetty <c_vnaral@qti.qualcomm.com>,
        ath10k@lists.infradead.org
References: <1493217698-22451-1-git-send-email-c_vnaral@qti.qualcomm.com>
Cc: linux-wireless@vger.kernel.org
From: Felix Fietkau <nbd@nbd.name>
Message-ID: <40f2b7a2-7276-6de6-afc6-407348c92e70@nbd.name> (sfid-20170426_173206_719181_804288C4)
Date: Wed, 26 Apr 2017 17:29:16 +0200
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In-Reply-To: <1493217698-22451-1-git-send-email-c_vnaral@qti.qualcomm.com>
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Sender: linux-wireless-owner@vger.kernel.org

On 2017-04-26 16:41, Venkateswara Rao Naralasetty wrote:
> Channel active/busy time are showing incorrect
> (less than previous or sometimes zero) for
> successive survey dump command.
> 
> example:
> Survey data from wlan0
>         frequency:                      5180 MHz [in use]
>         channel active time:            54995 ms
>         channel busy time:              432 ms
>         channel receive time:           0 ms
>         channel transmit time:          59 ms
> Survey data from wlan0
>         frequency:                      5180 MHz [in use]
>         channel active time:            32592 ms
>         channel busy time:              254 ms
>         channel receive time:           0 ms
>         channel transmit time:          0 ms
> 
> This patch fix this issue by assigning 'wmi_bss_survey_req_type'
> as 'WMI_BSS_SURVEY_REQ_TYPE_READ'.
> 
> Firmware ver 10.4-3.4-00082
> Hardware QCA4019
> 
> Signed-off-by: Venkateswara Rao Naralasetty <c_vnaral@qti.qualcomm.com>
> ---
>  drivers/net/wireless/ath/ath10k/mac.c |    2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/net/wireless/ath/ath10k/mac.c b/drivers/net/wireless/ath/ath10k/mac.c
> index 9977829..87a9b55 100644
> --- a/drivers/net/wireless/ath/ath10k/mac.c
> +++ b/drivers/net/wireless/ath/ath10k/mac.c
> @@ -6621,7 +6621,7 @@ static void ath10k_reconfig_complete(struct ieee80211_hw *hw,
>  				  struct ieee80211_channel *channel)
>  {
>  	int ret;
> -	enum wmi_bss_survey_req_type type = WMI_BSS_SURVEY_REQ_TYPE_READ_CLEAR;
> +	enum wmi_bss_survey_req_type type = WMI_BSS_SURVEY_REQ_TYPE_READ;
Does the firmware read the registers directly, or does it accumulate the
results in a way that can't overflow?
If you don't clear the counters on reset, the overflow will be
problematic for the current-channel stats.
I think a better approach would be to use READ_CLEAR for in-use channels
and store the sum inside the driver.

- Felix