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Date:   Tue, 18 Dec 2018 15:27:56 +0100
From:   Jiri Pirko <jiri@resnulli.us>
To:     Jian-Hong Pan <starnight@g.ncu.edu.tw>
Cc:     Andreas =?iso-8859-1?Q?F=E4rber?= <afaerber@suse.de>,
        "David S . Miller" <davem@davemloft.net>,
        Alan Cox <gnomes@lxorguk.ukuu.org.uk>,
        linux-lpwan@lists.infradead.org, netdev@vger.kernel.org,
        "<linux-arm-kernel@lists.infradead.org\\" 
        <linux-arm-kernel@lists.infradead.org>,
        "linux-kernel@vger.kernel.org>," <linux-kernel@vger.kernel.org>,
        Marcel Holtmann <marcel@holtmann.org>,
        Dollar Chen <dollar.chen@wtmec.com>,
        Ken Yu <ken.yu@rakwireless.com>,
        linux-wpan - ML <linux-wpan@vger.kernel.org>
Subject: Re: [PATCH v5 5/6] net: maclorawan: Implement maclorawan class module
Message-ID: <20181218142756.GA2031@nanopsycho>
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Tue, Dec 18, 2018 at 03:27:09PM CET, starnight@g.ncu.edu.tw wrote:
>> Sun, Dec 16, 2018 at 11:18:59AM CET, starnight@g.ncu.edu.tw wrote:
>> >LoRaWAN defined by LoRa Alliance(TM) is the MAC layer over LoRa devices.
>> >
>> >This patch implements part of Class A end-devices SoftMAC defined in
>> >LoRaWAN(TM) Specification Ver. 1.0.2:
>> >1. End-device receive slot timing
>> >2. Only single channel and single data rate for now
>> >3. Unconfirmed data up/down message types
>> >
>> >On the other side, it defines the basic interface and operation
>> >functions for compatible LoRa device drivers.
>> >
>> >Signed-off-by: Jian-Hong Pan <starnight@g.ncu.edu.tw>
>> >---
>> >V2:
>> >- Split the LoRaWAN class module patch in V1 into LoRaWAN socket and
>> >  LoRaWAN Soft MAC modules
>> >- Modify for Big/Little-Endian
>> >- Use SPDX license identifiers
>> >
>> >V3:
>> >- Remove the decoration word - inline of the functions
>> >- Order local variables from longest to shortest line in the functions
>> >- Change the calling mac_cb function to lrw_get_mac_cb macro
>> >
>> >V4:
>> >- Fix the delay period between RX window#1 and window#2
>> >- Fix by coding style report from scripts/checkpatch.pl
>> >
>> >V5:
>> >- Initial rx_skb_list when it is allocated with LoRa hardware
>> >- Check the sk_buff's data length before access it
>> >- Deal FPort field and decrypt payload in lrw_parse_frame function
>> >- Drop the recieved frame if parse failed
>> >- Fix the bug which passes wrong skb properties from maclorawan to lorawan module
>> >
>> > net/maclorawan/Kconfig  |  14 +
>> > net/maclorawan/Makefile |   2 +
>> > net/maclorawan/mac.c    | 555 ++++++++++++++++++++++++++++++++++++
>> > net/maclorawan/main.c   | 606 ++++++++++++++++++++++++++++++++++++++++
>> > 4 files changed, 1177 insertions(+)
>> > create mode 100644 net/maclorawan/Kconfig
>> > create mode 100644 net/maclorawan/Makefile
>> > create mode 100644 net/maclorawan/mac.c
>> > create mode 100644 net/maclorawan/main.c
>>
>>
>> I don't get it. In patch "Add LoRaWAN API declaration for LoRa devices"
>> you add headers for "API" and here you implement functions. That is just
>> weird. Does it mean you can have other implementations?
>
>LoRaWAN defined by LoRa Alliance(TM) is the MAC layer over LoRa PHY.
>This part is soft-MAC as Andreas mentioned
>http://lists.infradead.org/pipermail/linux-lpwan/2018-December/000010.html

Okay, that does not answer my concern about header file in one patch and
the actual implementation of functions in another one.


>
>> Also, you don't really have any user of this API in the set. Please
>> introduce at least 1 driver, preferably more (I see that Andreas has
>> multiple ones in his patchset). You cannot push kernel infrastructure
>> without kernel user.
>
>The soft-MAC is suitable for the LoRa chips' device drivers, like
>sx1276/77/78/79, RFM95/96/97/98W ...
>Still waiting for Andreas' sx1276 version 2 patch and more discussion.
>For example, how to make PF_LORA and PF_LORAWAN like Ethernet, PF_INET
>and PF_INET6 don't need separate devices either, both use eth0.
>https://lkml.org/lkml/2018/8/3/266

Then you should push this is RFC or together with Andreases work in a
single patchset. Infra without users cannot be merged.


>
>Jian-Hong Pan