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Date: Wed, 26 Feb 2025 00:45:45 +0100
From: Danilo Krummrich <dakr@kernel.org>
To: Jason Gunthorpe <jgg@nvidia.com>
Cc: Joel Fernandes <joelagnelf@nvidia.com>,
	Alexandre Courbot <acourbot@nvidia.com>,
	Dave Airlie <airlied@gmail.com>, Gary Guo <gary@garyguo.net>,
	Joel Fernandes <joel@joelfernandes.org>,
	Boqun Feng <boqun.feng@gmail.com>,
	John Hubbard <jhubbard@nvidia.com>, Ben Skeggs <bskeggs@nvidia.com>,
	linux-kernel@vger.kernel.org, rust-for-linux@vger.kernel.org,
	nouveau@lists.freedesktop.org, dri-devel@lists.freedesktop.org,
	paulmck@kernel.org
Subject: Re: [RFC PATCH 0/3] gpu: nova-core: add basic timer subdevice
 implementation
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In-Reply-To: <20250225225756.GA4959@nvidia.com>

On Tue, Feb 25, 2025 at 06:57:56PM -0400, Jason Gunthorpe wrote:
> The common driver shutdown process in the kernel, that is well tested
> and copied, makes the driver single threaded during the remove()
> callback.

All devres callbacks run in the same callchain, __device_release_driver() first
calls remove() and then all the devres callbacks, where we revoke the pci::Bar,
by which gets dropped and hence the bar is unmapped and resource regions are
free. It's not different to C drivers. Except that in C you don't lose access to
the void pointer that still points to the (unmapped) MMIO address.