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 6D20AEEC0; Wed, 22 Apr 2026 10:55:27 +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=1776855327; cv=none; b=jpuA573BIWdVk72lDQl8P1S8XZCaIoYfoWvBHKg37Ssr3FMBnvhor/CSmHV//Z23VC6kTO4+zQzC3cIifHNJbutj/sbyumLGDQaQShEkr0Va+hvnoTG345okCJbPJ1YJsLfkTwpYHvK9HEQXnNtaujAsNo2jwriA+Q4QAJmfCGI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1776855327; c=relaxed/simple; bh=Cv/dvtt9j+p8MbtSj7Sysg2FpL5y9fNb3weRLkynaWU=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=dBjME7YrnCM9kKmrxEzPG4cqCogfh8UjJat7dgF/YkZpxiMu3PXBeAEV5HrgnkrhNNqzo4UhzVyq5wf//Kb6uga33tctBgg4c7WphDZ9wgODJyDYCp1tVGiD1qtyICpiAPC/5sxdSbKQK4PSkAt2lJJ9FHPmnBh86P1sFb775tQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=ArQE3mYU; 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="ArQE3mYU" Received: by smtp.kernel.org (Postfix) with ESMTPSA id EAEDDC19425; Wed, 22 Apr 2026 10:55:20 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1776855327; bh=Cv/dvtt9j+p8MbtSj7Sysg2FpL5y9fNb3weRLkynaWU=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=ArQE3mYUDYrhzX+54sLB9RhfxEf5H81CS8mcbi8mUaELpUurEgvq9posUW1zfxq6u GX6wuyTtjA3YLevsf+u39UeeqLTY3Z0nJlD/VZOOapW+QFvCJttxJRHSmbDVL+plNg i2Ozp3hU7kcwCQR4y+eAgFN0veEmgAdsohrCK2fa3JPWa+hKy98tmpEPLfemuLS55b Nzzn4MX5/ehEIhigE2mtIobktFku2Bl5yBSTzYzHh44GLABvYxfFPgjjcjr4EpgB6a dC1GlMsWFvHbhiSyINSlWef96SBv64+oya2Aqy8R6UidGyiD2vfjRuPfYSlP2idFmv hE3qjQvZPG9sA== Date: Wed, 22 Apr 2026 11:55:16 +0100 From: Simon Horman To: Jakub Kicinski Cc: davem@davemloft.net, netdev@vger.kernel.org, edumazet@google.com, pabeni@redhat.com, andrew+netdev@lunn.ch, corbet@lwn.net, skhan@linuxfoundation.org, marcel@holtmann.org, luiz.dentz@gmail.com, mchehab+huawei@kernel.org, jani.nikula@intel.com, gregkh@linuxfoundation.org, demarchi@kernel.org, rdunlap@infradead.org, justonli@chromium.org, ivecera@redhat.com, jonathan.cameron@huawei.com, kees@kernel.org, marco.crivellari@suse.com, ferr.lambarginio@gmail.com, nihaal@cse.iitm.ac.in, mingo@kernel.org, tglx@kernel.org, linmq006@gmail.com, linux-doc@vger.kernel.org, linux-bluetooth@vger.kernel.org Subject: Re: [PATCH net-deletions] net: remove ISDN subsystem and Bluetooth CMTP Message-ID: <20260422105516.GN651125@horms.kernel.org> References: <20260421022108.1299678-1-kuba@kernel.org> Precedence: bulk X-Mailing-List: linux-bluetooth@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20260421022108.1299678-1-kuba@kernel.org> On Mon, Apr 20, 2026 at 07:21:07PM -0700, Jakub Kicinski wrote: > Remove the ISDN (mISDN, CAPI) subsystem and Bluetooth CMTP protocol > from the kernel tree. > > ISDN is a pretty old technology and it's unclear whether anyone still > uses it. I went over the last few years of git history and all the > commits are either tree-wide conversions or syzbot/static analyzer > fixes. > > When we discussed removal in the past IIRC there were some concerns > about ISDN still being used in parts of Germany. Unfortunately, the > code base is quite old, none of the current maintainers are familiar > with it and AI tools will have a field day finding bugs here. > > Delete this code and preserve it in an out-of-tree repository > for any remaining users: > https://github.com/linux-netdev/mod-orphan > > UAPI constants AF_ISDN/PF_ISDN and the SELinux isdn_socket class > are preserved for ABI stability, but the rest of uAPI is removed. > > Signed-off-by: Jakub Kicinski Reviewed-by: Simon Horman