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Date: Mon, 28 Apr 2025 23:21:21 +0200
From: Danilo Krummrich <dakr@kernel.org>
To: Rob Herring <robh@kernel.org>
Cc: Dirk Behme <dirk.behme@de.bosch.com>, Dirk Behme <dirk.behme@gmail.com>,
	Remo Senekowitsch <remo@buenzli.dev>,
	Saravana Kannan <saravanak@google.com>,
	Miguel Ojeda <ojeda@kernel.org>,
	Alex Gaynor <alex.gaynor@gmail.com>,
	Boqun Feng <boqun.feng@gmail.com>, Gary Guo <gary@garyguo.net>,
	=?iso-8859-1?Q?Bj=F6rn?= Roy Baron <bjorn3_gh@protonmail.com>,
	Benno Lossin <benno.lossin@proton.me>,
	Andreas Hindborg <a.hindborg@kernel.org>,
	Alice Ryhl <aliceryhl@google.com>, Trevor Gross <tmgross@umich.edu>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	"Rafael J. Wysocki" <rafael@kernel.org>,
	linux-kernel@vger.kernel.org, devicetree@vger.kernel.org,
	rust-for-linux@vger.kernel.org
Subject: Re: [PATCH v3 3/7] rust: property: Introduce PropertyGuard
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In-Reply-To: <20250428204840.GB1572343-robh@kernel.org>

On Mon, Apr 28, 2025 at 03:48:40PM -0500, Rob Herring wrote:
> 
> One thing that's really hard to debug in C drivers is where an 
> error came from. You can for example turn on initcall_debug and see that 
> a driver probe returned an error. It's virtually impossible to tell 
> where that originated from. The only way to tell is with prints. That is 
> probably the root of why probe has so many error prints. I think we can 
> do a lot better with rust given Result can hold more than just an int. 

This I fully agree with, not sure if the solution is to put more stuff into the
Result type though. However, there are things like #[track_caller] (also
recently mentioned by Benno), which might be a good candidate for improving this
situation.

As mentioned, for now let's go with

	pub fn required_by(self, dev: &Device) -> Result<T>

additional to required() for this purpose to get a proper dev_err() print.