From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.6 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id D3021C43381 for ; Thu, 11 Feb 2021 09:15:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id ABA7764E3C for ; Thu, 11 Feb 2021 09:15:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229887AbhBKJPa (ORCPT ); Thu, 11 Feb 2021 04:15:30 -0500 Received: from mail.kernel.org ([198.145.29.99]:41018 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229906AbhBKJGa (ORCPT ); Thu, 11 Feb 2021 04:06:30 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id 9401161493; Thu, 11 Feb 2021 09:04:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1613034267; bh=s6acHd5aTlo6n49Lkwr18bw9K57h309+9vm78Ih2dCs=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=FSKUkhCP0g6VmedvF0aQPzYO/lYhn/RcbMV0JRzgpFyE/rDvhQrg7OmQqIzg9QY/o Br5NJKne3Pwkg3tM5tqcBFuA8wC+q3PJhuw4o2LCYFB5WeFLw7Oe66FREsGB7f0S9G 3/y5QjdVlw00Ad21aCTdCJO3HWBFrO/TGLDzq6HtAe+spCQp6ToWzcMC/eqU+7iZnV WATuk84moqqfkcSNSAw+eRdg5AILaUN8b2t1XX6yYuXlhwW7N4UGO3kwP3ZTXWSYXt ruq2eJVnbfs+EUT63+OD7fm30X4eSV4dZgWRvKOe4UXMj9KPX7YzhOAjBXfKmKrvos yLs5VeWaf5d9g== Received: from johan by xi.lan with local (Exim 4.93.0.4) (envelope-from ) id 1lA7ty-0004kk-Dl; Thu, 11 Feb 2021 10:04:42 +0100 Date: Thu, 11 Feb 2021 10:04:42 +0100 From: Johan Hovold To: Pavel Machek Cc: Greg KH , kernel list , phone-devel@vger.kernel.org, tony@atomide.com Subject: Re: [RFC/context] add serdev interfaces to n_gsm Message-ID: References: <20210107224530.GA23250@duo.ucw.cz> <20210131170639.GA21067@duo.ucw.cz> <20210210212836.GA18497@duo.ucw.cz> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="rAT/ssUU3GkMr7C/" Content-Disposition: inline In-Reply-To: <20210210212836.GA18497@duo.ucw.cz> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org --rAT/ssUU3GkMr7C/ Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Wed, Feb 10, 2021 at 10:28:36PM +0100, Pavel Machek wrote: > Hi! >=20 > > > > +config GNSS_MOTMDM > > > > + tristate "Motorola Modem TS 27.010 serdev GNSS receiver support" > > > > + depends on SERIAL_DEV_N_GSM > > >=20 > > > You need to post this driver together with the serdev-ngsm driver. Th= is > > > one cannot currently even be built without it, but we also need to see > > > the greater picture here. > >=20 > > Well, here it is, for greater picture. But it is not ready. Current > > problem I have is gsm_serdev_register_tty_port(). The way I do > > platform device registration causes oops on module unload. Help with > > that would be welcome >=20 > I would not mind comments on parent patch and some help here. >=20 > Basically I tried to work around limitation in=20 >=20 > int serdev_device_add(struct serdev_device *serdev) > { > ... > /* Only a single slave device is currently supported. */ > if (ctrl->serdev) { > ... I haven't really had time to look at the code yet, but trying to work around the single-client (slave) assumption seems wrong. You still have only one client per port even if the mux driver provides multiple (virtual) ports. But judging from a quick look it appears that you are indeed registering one tty device per mux channel in gsm_serdev_register_tty_port() (as you should) so perhaps that's not the issue here. Do you have a stack trace from the oops? Are the client drivers holding the ports open while you unload the parent driver? That sounds like something which could go boom unless you pin the parent for example (serdev doesn't support hangups). Also, did you forget to post the gsm_tty_driver implementation? I don't see a definition of that symbol in the patch. Johan --rAT/ssUU3GkMr7C/ Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iHUEABYIAB0WIQQHbPq+cpGvN/peuzMLxc3C7H1lCAUCYCTzJAAKCRALxc3C7H1l CI+3AP9VA3K/m2t9z13w7b+tVZbUIrSxHOX/0DomC+lfFgg1pQD/ZE+MdHa704R5 sm2pYuZFeNCfY6aLbitWO0uLlnOZPQo= =LyzA -----END PGP SIGNATURE----- --rAT/ssUU3GkMr7C/--