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Date: Fri, 01 May 2026 23:55:03 +0200
Message-Id: <DI7OB6BEZJ69.VM54A4U4P68A@kernel.org>
Subject: Re: [PATCH v3 3/5] rust: io: use the `bitfield!` macro in
 `register!`
Cc: "Alexandre Courbot" <acourbot@nvidia.com>, "Joel Fernandes"
 <joelagnelf@nvidia.com>, "Yury Norov" <yury.norov@gmail.com>, "Miguel
 Ojeda" <ojeda@kernel.org>, "Boqun Feng" <boqun@kernel.org>, "Gary Guo"
 <gary@garyguo.net>, =?utf-8?q?Bj=C3=B6rn_Roy_Baron?=
 <bjorn3_gh@protonmail.com>, "Benno Lossin" <lossin@kernel.org>, "Andreas
 Hindborg" <a.hindborg@kernel.org>, "Alice Ryhl" <aliceryhl@google.com>,
 "Trevor Gross" <tmgross@umich.edu>, "Daniel Almeida"
 <daniel.almeida@collabora.com>, "David Airlie" <airlied@gmail.com>, "Simona
 Vetter" <simona@ffwll.ch>, "John Hubbard" <jhubbard@nvidia.com>, "Alistair
 Popple" <apopple@nvidia.com>, "Timur Tabi" <ttabi@nvidia.com>, "Zhi Wang"
 <zhiw@nvidia.com>, "Eliot Courtney" <ecourtney@nvidia.com>,
 <linux-kernel@vger.kernel.org>, <rust-for-linux@vger.kernel.org>,
 <nova-gpu@lists.linux.dev>, <driver-core@lists.linux.dev>
To: "Yury Norov" <ynorov@nvidia.com>
From: "Danilo Krummrich" <dakr@kernel.org>
References: <20260501-bitfield-v3-0-aa1076c3337d@nvidia.com>
 <20260501-bitfield-v3-3-aa1076c3337d@nvidia.com> <afTnQ1KCyybUE3pH@yury>
 <DI7JQ529XI9V.QMFHCU2HMGSN@kernel.org> <afUP9laA5xYWBuc2@yury>
In-Reply-To: <afUP9laA5xYWBuc2@yury>

On Fri May 1, 2026 at 10:41 PM CEST, Yury Norov wrote:
> On Fri, May 01, 2026 at 08:19:31PM +0200, Danilo Krummrich wrote:
>> On Fri May 1, 2026 at 7:47 PM CEST, Yury Norov wrote:
>> > If it comes to another round, maybe split switching to a bitfields and
>> > getting rid of the bitfield_core? For maintainability reasons.
>>=20
>> I'm happy to take it as a single patch -- the deleted rules are dead cod=
e the
>> moment the switch happens, and the code is local to the same macro, so t=
he
>> intermediate state doesn't seem to add any value, or structure in terms =
of
>> touching different components etc.
>>=20
>> Did you have anything specific in mind when you mention maintainability =
reasons?
>
> I only mean that if there will be weird regression found in the new
> implementation, it's better to be able to revert just a single patch
> to restore the original code with no side effects.

Indeed, but by splitting it up that wouldn't be possible anymore, no?

Am I missing something?