Re: [PATCH] ath10k : Fix channel survey dump

From: Adrian Chadd <adrian@freebsd.org>
To: Kalle Valo <kvalo@qca.qualcomm.com>
Cc: "nbd@nbd.name" <nbd@nbd.name>,
	Venkateswara Naralasettty <vnaralas@qti.qualcomm.com>,
	"ath10k@lists.infradead.org" <ath10k@lists.infradead.org>,
	"linux-wireless@vger.kernel.org" <linux-wireless@vger.kernel.org>
Subject: Re: [PATCH] ath10k : Fix channel survey dump
Date: Fri, 19 May 2017 08:32:54 -0700	[thread overview]
Message-ID: <CAJ-Vmok6UXVpYfK5c_tDnFGN1uLfx+sGp0W2zFppB=TYtax72g@mail.gmail.com> (raw)
In-Reply-To: <87wp9durwe.fsf@kamboji.qca.qualcomm.com>

On 19 May 2017 at 02:17, Kalle Valo <kvalo@qca.qualcomm.com> wrote:
> Felix Fietkau <nbd@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.

[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