From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 8EE3032C8B; Fri, 6 Dec 2024 07:44:49 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1733471089; cv=none; b=RGE5+BdUK8VnpFnFpDJw3Qb98lOcv20tQeuO0CwBgyG3JIqs1UGLDL2i57j8HBT/3nZH5JPfNc1vPVZuAlh2gkdAKydy4AnqH3wlRQWaSYES+h9FJvQ1cEPiibhVk2+noU6D6g2K+rwl1SC4N7WFxraz9vv/yoIiM5ueNKbAyfE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1733471089; c=relaxed/simple; bh=CfzG560eBtBK6aHbLV/Ulyg9yy2XbK0ZTDl7TzDnaww=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=VG1z6o5PobukRNWGhE/qfiXUOdF7XDcAOymMzPR8prfy8OiANtUuCBUpWVKc1TC8IgWVft7TWXyv/zCMWuauMPTGH6huxsgwnxu1m3z6KHk5+WTYWzOoVQd+0GoRQMze/Vx+dXq6xjD3d2BrS4C4ShlghZ691CdZT56sd6xrvGM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=VYaFThl7; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="VYaFThl7" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 840FFC4CED1; Fri, 6 Dec 2024 07:44:46 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1733471089; bh=CfzG560eBtBK6aHbLV/Ulyg9yy2XbK0ZTDl7TzDnaww=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=VYaFThl79cHLQiWcmW/AHa/dJSh4GTWmawNN8PRDgft/uzry3U5KQnfzCvHjn/ZzU JPXxQB/5aBMkX7T/Q/sPkofvBIcacHPmzc2DTLl+EvqqDT225/UpMpq9QS0DLukpbo 2G66pw7osWh2BcCYU/Stk3nliD+RoMMoIZEicBa/2EJ8S9dXG7bauv2K10iqU0IUE1 0rYuATt5HE0yOYP+/UtxQTy3Bm71aSFOdLekocc0sQxDu87LqAB01lUT75vYdtwYT4 JZYJRrRimwgGZueS5SJ7NAoAcwbUvuWNZ1BuYn+FU6jjdcrNSJw4od+qMcyPZRnK5d 8t8ZChRHRhPWg== Date: Fri, 6 Dec 2024 07:44:43 +0000 From: Lee Jones To: Greg KH Cc: linux-kernel@vger.kernel.org, arnd@arndb.de, ojeda@kernel.org, alex.gaynor@gmail.com, boqun.feng@gmail.com, gary@garyguo.net, bjorn3_gh@protonmail.com, benno.lossin@proton.me, a.hindborg@kernel.org, aliceryhl@google.com, tmgross@umich.edu, rust-for-linux@vger.kernel.org Subject: Re: [PATCH v3 0/5] rust: miscdevice: Provide sample driver using the new MiscDevice bindings Message-ID: <20241206074443.GJ8882@google.com> References: <20241205162531.1883859-1-lee@kernel.org> <2024120632-hardwired-hardhead-1906@gregkh> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <2024120632-hardwired-hardhead-1906@gregkh> On Fri, 06 Dec 2024, Greg KH wrote: > On Thu, Dec 05, 2024 at 04:25:17PM +0000, Lee Jones wrote: > > It has been suggested that the driver should use dev_info() instead of > > pr_info() however there is currently no scaffolding to successfully pull > > a 'struct device' out from driver data post register(). This is being > > worked on and we will convert this over in due course. > > But the miscdevice.rs change provides this to you, right? Or if not, > why not? This does allow us to pull the 'struct device *` out from `struct miscdevice`; however, since this resides in MiscDeviceRegistration, which we lose access to after .init, we have no means to call it. Alice is going to work on a way to use ThisModule to get the MiscDeviceRegistration reference back from anywhere in the module. Until that piece lands, we can't call MiscDeviceRegistration::device() outside of RustMiscDeviceModule. One option that I investigated involved global mutable variable that we could store the &Device into during MiscDeviceRegistration, however this got messy (actually just bloaty) fast. Alice's solution will be cleaner and more universally useful. -- Lee Jones [李琼斯]