linux-kernel - Re: [PATCH v4 14/16] power: supply: bd71828: Support wider register addresses

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <2334e57c-a384-4a1e-9708-19d14b8f082c@gmail.com>
Date: Fri, 14 Nov 2025 15:22:00 +0200
From: Matti Vaittinen <mazziesaccount@...il.com>
To: Andreas Kemnade <andreas@...nade.info>,
 Matti Vaittinen <matti.vaittinen@...ux.dev>
Cc: Matti Vaittinen <matti.vaittinen@...rohmeurope.com>,
 Lee Jones <lee@...nel.org>, Pavel Machek <pavel@...nel.org>,
 Rob Herring <robh@...nel.org>, Krzysztof Kozlowski <krzk+dt@...nel.org>,
 Conor Dooley <conor+dt@...nel.org>, Sebastian Reichel <sre@...nel.org>,
 Liam Girdwood <lgirdwood@...il.com>, Mark Brown <broonie@...nel.org>,
 Michael Turquette <mturquette@...libre.com>, Stephen Boyd
 <sboyd@...nel.org>, Linus Walleij <linus.walleij@...aro.org>,
 Bartosz Golaszewski <brgl@...ev.pl>,
 Alexandre Belloni <alexandre.belloni@...tlin.com>,
 linux-leds@...r.kernel.org, devicetree@...r.kernel.org,
 linux-kernel@...r.kernel.org, linux-pm@...r.kernel.org,
 linux-clk@...r.kernel.org, linux-gpio@...r.kernel.org,
 linux-rtc@...r.kernel.org
Subject: Re: [PATCH v4 14/16] power: supply: bd71828: Support wider register
 addresses

Thanks Andreas,

On 14/11/2025 13:15, Andreas Kemnade wrote:
> On Thu, 13 Nov 2025 10:55:39 +0200
> Matti Vaittinen <matti.vaittinen@...ux.dev> wrote:
> 
>> As a side note, we can reduce the "wasted space / member / instance" from
>> 3 bytes to 1 byte, by using u16 instead of the unsigned int if needed. I
>> rather use unsigned int to be initially prepared for devices with 32 bit
>> registers if there is no need to count bytes.
> 
> Well, this is totally internal to the module, so no ABI/API changes, so
> there is no advantage of using 32bit now I think. We can switch any time.

The only advantage is to avoid the churn if 32bit ICs are to be added.

> But we have 32bit stuff in the regmap cache anyways, so that is not above
> the general level of wasting space.

Exactly. And, I am not sure if sparing ~hundred bytes is worth the 
hassle - even if it is hassle internal to the driver. But yeah, we can 
squeeze a few bytes if it is seen beneficial. That's why I mentioned it 
here :)

Yours,
	-- Matti

---
Matti Vaittinen
Linux kernel developer at ROHM Semiconductors
Oulu Finland

~~ When things go utterly wrong vim users can always type :help! ~~