From: "Valo, Kalle" <kvalo@qca.qualcomm.com>
To: Lior David <liord@codeaurora.org>
Cc: Arend Van Spriel <arend.vanspriel@broadcom.com>,
qca_merez <qca_merez@qca.qualcomm.com>,
qca_liord <qca_liord@qca.qualcomm.com>,
"linux-wireless@vger.kernel.org" <linux-wireless@vger.kernel.org>,
wil6210 <wil6210@qca.qualcomm.com>
Subject: Re: [PATCH v2 01/13] wil6210: add sysfs file for FTM calibration
Date: Sat, 28 Jan 2017 06:32:38 +0000 [thread overview]
Message-ID: <87ziib3da5.fsf@kamboji.qca.qualcomm.com> (raw)
In-Reply-To: <7da1de20-8040-fc3b-0c1d-77c5fa98d0f5@codeaurora.org> (Lior David's message of "Mon, 23 Jan 2017 16:55:26 +0200")
Lior David <liord@codeaurora.org> writes:
> On 1/19/2017 3:14 PM, Arend Van Spriel wrote:
>> On 19-1-2017 13:36, Lior David wrote:
>>> On 1/19/2017 2:24 PM, Valo, Kalle wrote:
>>>> Maya Erez <qca_merez@qca.qualcomm.com> writes:
>>>>
>>>>> From: Lior David <qca_liord@qca.qualcomm.com>
>>>>>
>>>>> In fine timing measurements, the calculation is affected by
>>>>> 2 parts: timing of packets over the air, which is platform
>>>>> independent, and platform-specific delays, which are dependent
>>>>> on things like antenna cable length and type.
>>>>> Add a sysfs file which allows to get/set these platform specific
>>>>> delays, separated into the TX and RX components.
>>>>> There are 2 key scenarios where the file can be used:
>>>>> 1. Calibration - start with some initial values (for example,
>>>>> the default values at startup), make measurements at a known
>>>>> distance, then iteratively change the values until the
>>>>> measurement results match the known distance.
>>>>> 2. Adjust the delays when platform starts up, based on known
>>>>> values.
>>>>>
>>>>> Signed-off-by: Lior David <qca_liord@qca.qualcomm.com>
>>>>> Signed-off-by: Maya Erez <qca_merez@qca.qualcomm.com>
>>>>
>>>> Can't this go via nl80211? sysfs is not really supposed to be used for
>>>> something like this.
>>>>
>>> There is no nl80211 API for this (yet?).
>>=20
>> So come up with one...?
> I checked this further and had some more internal discussion.
> This change is only about FTM calibration which is highly vendor specific=
so I
> don't think NL80211 API is appropriate for it. Since it is needed in prod=
uction
> (to calibrate the platform after boot using pre-computed values)
For calibration and manufacturing testing we have NL80211_CMD_TESTMODE,
which is a vendor specific interface.
> I think sysfs is a reasonable place for it.
Wireless drivers really should not use sysfs. I guess there might be
valid cases when using sysfs is ok but I can't really come up with
anything right now.
--=20
Kalle Valo=
next prev parent reply other threads:[~2017-01-28 6:45 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-01-12 13:05 [PATCH v2 00/13] wil6210 patches Maya Erez
2017-01-12 13:05 ` [PATCH v2 01/13] wil6210: add sysfs file for FTM calibration Maya Erez
2017-01-19 12:24 ` Valo, Kalle
2017-01-19 12:36 ` Lior David
2017-01-19 13:14 ` Arend Van Spriel
2017-01-23 14:55 ` Lior David
2017-01-28 6:32 ` Valo, Kalle [this message]
2017-01-12 13:05 ` [PATCH v2 02/13] wil6210: add disable_ap_sme module parameter Maya Erez
2017-01-27 17:50 ` [v2,02/13] " Kalle Valo
2017-01-12 13:05 ` [PATCH v2 03/13] wil6210: support loading dedicated image for sparrow-plus devices Maya Erez
2017-01-12 13:05 ` [PATCH v2 04/13] wil6210: remove __func__ from debug printouts Maya Erez
2017-01-12 13:05 ` [PATCH v2 05/13] wil6210: support new WMI-only FW capability Maya Erez
2017-01-12 13:05 ` [PATCH v2 06/13] wil6210: missing reinit_completion in wmi_call Maya Erez
2017-01-12 13:05 ` [PATCH v2 07/13] wil6210: protect against false interrupt during reset sequence Maya Erez
2017-01-12 13:06 ` [PATCH v2 08/13] wil6210: fix for broadcast workaround in PBSS Maya Erez
2017-01-12 13:06 ` [PATCH v2 09/13] wil6210: align to latest auto generated wmi.h Maya Erez
2017-01-12 13:06 ` [PATCH v2 10/13] wil6210: report association ID (AID) per station in debugfs Maya Erez
2017-01-12 13:06 ` [PATCH v2 11/13] wil6210: option to override A-BFT length in start AP/PCP Maya Erez
2017-01-12 13:06 ` [PATCH v2 12/13] wil6210: set dma mask to reflect device capability Maya Erez
2017-01-12 20:27 ` merez
2017-01-13 8:20 ` [v2,12/13] " Kalle Valo
2017-01-12 13:06 ` [PATCH v2 13/13] wil6210: convert symbolic permissions to octal permissions Maya Erez
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