Subject: Re: [PATCH 00/11] net: wwan: t9xx: Add MediaTek T9XX WWAN driver

From: Sergey Ryazanov <[email-masked]>
Date: Tue, 2 Jun 2026 23:46:59 +0300

Hi,

let me join the discussion and put my 2c.

On 6/2/26 13:58, Wu. JackBB (GSM) wrote:
> Hi Jakub,
> 
>> On Fri, 29 May 2026 18:31:39 +0800 Jack Wu via B4 Relay wrote:
>>> 43 files changed, 14761 insertions(+)
>>
>> Please try to cut this down to ~5kLoC for the initial submission.
>> Whatever the absolute minimum sensible chunk of code is.
>>
>> Each patch must build cleanly with W=1
> 
> We've already reduced this significantly from the original 41k LoC
> down to ~14.7k by stripping out non-essential features such as
> exception handling, memory logging, devlink, statistics, debug
> tracing, and others.
> 
> We even removed some arguably necessary features (PM, mdlog,
> throughput optimizations) that we plan to submit as follow-up
> series.

Great work. Highly appreciate!

> Note that the line count may slightly increase in v2, as we plan
> to add missing kdoc comments based on review feedback.
> 
> For reference, the t7xx driver (two generations older, simpler HW)
> had an initial submission of ~11.3k LoC [1]. The t9xx hardware is
> more complex, so we believe being in a similar range is reasonable.

Let me elaborate a bit here. The size problem is not due to a git or a 
mailbox limitation. It arise due to the human limitation. The T7xx 
submission review took something about 4 months and 8 iterations. And it 
was 'only' 11.3k lines. Let's do some extrapolation assuming that 
function is linear. 14.7k is 30% bigger, thus, estimated reviewing time 
should be 5 months and 2 weeks. And this looks optimistic.

Recommendation, shared by Jakub, is practical. 5k lines might be 
reviewed in a reasonable time and merged with the full confidence of the 
quality.

> We'd like to keep the driver functional and reviewable in its
> current scope. Do you have any suggestions on how we could further
> reduce the size while maintaining a working initial submission?

Off the top of my head, I would suggest joining T7xx and T9xx code 
bases. It could be done through factoring out a core functionality of 
T7xx into a library, or through making the driver layered.

I am not pretending being an expert in any of these drivers, but 
generally divide-n-conqueror together with code reuse work reliable. As 
an alternative, I could spend a couple of weeks reviewing the new 
submission and will come with more specific ideas on what can be thrown 
away or reused.

> [1] https://patchwork.kernel.org/project/netdevbpf/cover/[email-masked]/
> 
> Thanks.
> 
> 
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And this disclaimer does not facilitate the review. Am I 'intended' 
recipient or should I destroy the message ASAP?

--
Sergey