RE: [PATCH] ath10k : Fix channel survey dump

[Venkateswara Naralasettty]

-Original Message-
From: Kalle Valo 
Sent: Friday, May 19, 2017 2:48 PM
To: n...@nbd.name
Cc: Venkateswara Naralasettty <vnara...@qti.qualcomm.com>; 
ath...@lists.infradead.org; linux-wireless@vger.kernel.org
Subject: Re: [PATCH] ath10k : Fix channel survey dump

Felix Fietkau <n...@nbd.name> writes:

> 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_vna...@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.

Venkateswara, any comments?

--
Kalle Valo

Sorry for the delayed response I held up with some other work. Currently I am 
working with firmware team to address your comments.

--
Venkatesh.

Re: [PATCH] ath10k : Fix channel survey dump

[Johannes Berg]

On Fri, 2017-05-19 at 08:32 -0700, Adrian Chadd wrote:
> 
> I just bumped into this at work. I'm thinking of teaching mac80211
> about optionally summing things so each driver doesn't need another
> per-channel array.
> 

We could possibly even do that in cfg80211, I guess.

johannes

Re: [PATCH] ath10k : Fix channel survey dump

[Adrian Chadd]

On 19 May 2017 at 02:17, Kalle Valo  wrote:
> Felix Fietkau  writes:
>
>> 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.

[snip]

>> 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.
>
> Venkateswara, any comments?

I just bumped into this at work. I'm thinking of teaching mac80211
about optionally summing things so each driver doesn't need another
per-channel array.



-adrian

Re: [PATCH] ath10k : Fix channel survey dump

[Kalle Valo]

Felix Fietkau  writes:

> 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 
>> ---
>>  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.

Venkateswara, any comments?

-- 
Kalle Valo

Re: [PATCH] ath10k : Fix channel survey dump

[Felix Fietkau]

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 
> ---
>  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