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 D96B725D546 for ; Mon, 13 Oct 2025 16:14:28 +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=1760372069; cv=none; b=C+tzYUysYjS6pMq0yAqndV7AbaZ25E6rhoBw7AVPB/aBFOWOsoSUVVQ36yPcmAinIHlBYT5Ru8LEzpIQNNNlF7bgrMhb257QZ4gIdBVOMbHDnUyzSRd8zEDEOgXEm7M4gpvP+ZY8cO6B1HwuXgYxwhTxkAi7w1YF1NGN3XGsx0M= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760372069; c=relaxed/simple; bh=VBeyRidS+H0e+1y24wGE652oyB2RWBYogmJk6MqQERU=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=tCj9kRfOC9lWi/gubucRRAmXHAqVXgL6rTxGSlElLEiQUJzTObrbvbdhjFPQSIizn7UdBNr4C6REdfcL3iDH/wP8W2tCabBxGgZXFYOmHtbKZaHHsHvMjCidlgX2wgSZ+wCdc60l8Qqh3QO2mqlyvLPPd471v0U9qi/6rMm+lro= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=zFpuzrVn; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="zFpuzrVn" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 15A01C4CEE7; Mon, 13 Oct 2025 16:14:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1760372068; bh=VBeyRidS+H0e+1y24wGE652oyB2RWBYogmJk6MqQERU=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=zFpuzrVn2mqSblgiBiPbz+6qhjTVZobwc7Lc6AD4VDWmJ9/MHf12EKbwa9LCix1Lx HkYQhiz5QNlMuM5K0LEd9ivC+qFJ1RV5PurSLbaGnen6nexOeRVBnodmSlDNXSCKoD nIqmCaqgB4y+QypwgeZdYG97sjd2KlB4CPxKrrnY= Date: Mon, 13 Oct 2025 18:14:25 +0200 From: Greg KH To: Alex Henrie Cc: Vojtech Pavlik , Oliver Neukum , linux-usb@vger.kernel.org, Johan Hovold Subject: Re: ttyACM versus ttyUSB Message-ID: <2025101339-snowbound-capsule-fc4a@gregkh> References: <2025101243-ongoing-truce-3aa5@gregkh> <2025101238-mastiff-decibel-4b4f@gregkh> <194258bf-e78c-46b8-8229-3b019f2b8ab0@suse.com> Precedence: bulk X-Mailing-List: linux-usb@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: On Mon, Oct 13, 2025 at 09:42:38AM -0600, Alex Henrie wrote: > > Today, some USB-serial chips have the ACM protocol, so perhaps it would > > make sense to merge the drivers, I certainly would not object. > > It is definitely confusing to have to think about whether your USB > serial device is going to appear as /dev/ttyUSB* or /dev/ttyACM*. On > the other hand, if we renamed the ttyACM device nodes to ttyUSB to > reflect the fact that ACM is just another USB serial protocol, how > many things would that break? In general I like making things make > sense, but I'm hesitant to be the one to pull the trigger. Yeah, we can't really do that now, sorry. Too many chances to break userspace. If you want to always get this right, just use the symlinks in /dev/serial/ to find the proper device easier. greg k-h