Message-ID: <46938937-0c73-6249-45f8-b0f65bfaf971@linux.intel.com>
Date:   Thu, 2 Dec 2021 12:44:31 -0800
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Subject: Re: [PATCH v2 09/14] net: wwan: t7xx: Add WWAN network interface
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To:     Sergey Ryazanov <ryazanov.s.a@gmail.com>
Cc:     netdev@vger.kernel.org, linux-wireless@vger.kernel.org,
        Jakub Kicinski <kuba@kernel.org>,
        David Miller <davem@davemloft.net>,
        Johannes Berg <johannes@sipsolutions.net>,
        Loic Poulain <loic.poulain@linaro.org>,
        M Chetan Kumar <m.chetan.kumar@intel.com>,
        chandrashekar.devegowda@intel.com,
        Intel Corporation <linuxwwan@intel.com>,
        chiranjeevi.rapolu@linux.intel.com, haijun.liu@mediatek.com,
        amir.hanania@intel.com,
        Andy Shevchenko <andriy.shevchenko@linux.intel.com>,
        dinesh.sharma@intel.com, eliot.lee@intel.com,
        mika.westerberg@linux.intel.com, moises.veleta@intel.com,
        pierre-louis.bossart@intel.com, muralidharan.sethuraman@intel.com,
        Soumya.Prakash.Mishra@intel.com, sreehari.kancharla@intel.com,
        suresh.nagaraj@intel.com
References: <20211101035635.26999-1-ricardo.martinez@linux.intel.com>
 <20211101035635.26999-10-ricardo.martinez@linux.intel.com>
 <CAHNKnsTAj8OHzoyK3SHhA_yXJrqc38bYmY6pYZf9fwUemcK7iQ@mail.gmail.com>
 <5755abe9-7b3c-0361-4eea-e0c125811eae@linux.intel.com>
 <CAHNKnsTARNNeiCBtDxmiMx2gUkKDb-V3e+xtfgsc-imeWv0CLA@mail.gmail.com>
From:   "Martinez, Ricardo" <ricardo.martinez@linux.intel.com>
In-Reply-To: <CAHNKnsTARNNeiCBtDxmiMx2gUkKDb-V3e+xtfgsc-imeWv0CLA@mail.gmail.com>
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Hi Sergey,

On 12/1/2021 1:09 PM, Sergey Ryazanov wrote:
> On Wed, Dec 1, 2021 at 9:06 AM Martinez, Ricardo
> <ricardo.martinez@linux.intel.com> wrote:
>> On 11/6/2021 11:08 AM, Sergey Ryazanov wrote:
>>> On Mon, Nov 1, 2021 at 6:57 AM Ricardo Martinez wrote:
>>>> +#define IPV4_VERSION           0x40
>>>> +#define IPV6_VERSION           0x60
>>> Just curious why the _VERSION suffix? Why not, for example, PKT_TYPE_ prefix?
>> Nothing special about _VERSION, but it does look a bit weird, will use
>> PKT_TYPE_  as suggested
> I checked the driver code again and found that these constants are
> really used to distinguish between IPv4 and IPv6 packets by checking
> the first byte of the data packet (IP header version field).
>
> Now I am wondering, does the modem firmware report a packet type in
> one of the BAT or PIT headers? If the modem is already reporting a
> packet type, then it is better to use the provided information instead
> of touching the packet data. Otherwise, if the modem does not
> explicitly report a packet type, and you have to check the version
> field of the IP header, then it seems Ok to keep the names of these
> constants as they are (with the _VERSION suffix).

Actually, there is a bit in the PIT header for the packet type, I'll 
make the driver

use it instead of looking at the data packet.