From nobody Thu Sep 11 14:42:24 2025 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id DB298C00528 for ; Fri, 4 Aug 2023 12:36:03 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229944AbjHDMgC (ORCPT ); Fri, 4 Aug 2023 08:36:02 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38266 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229476AbjHDMgA (ORCPT ); Fri, 4 Aug 2023 08:36:00 -0400 Received: from muru.com (muru.com [72.249.23.125]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id DB41546B3; Fri, 4 Aug 2023 05:35:55 -0700 (PDT) Received: from hillo.muru.com (localhost [127.0.0.1]) by muru.com (Postfix) with ESMTP id C0E8880F7; Fri, 4 Aug 2023 12:35:52 +0000 (UTC) From: Tony Lindgren To: Greg Kroah-Hartman , Jiri Slaby , Andy Shevchenko Cc: Andy Shevchenko , Dhruva Gole , =?UTF-8?q?Ilpo=20J=C3=A4rvinen?= , John Ogness , Johan Hovold , Sebastian Andrzej Siewior , Vignesh Raghavendra , linux-kernel@vger.kernel.org, linux-serial@vger.kernel.org Subject: [PATCH] serial: 8250: Reinit port_id when adding back serial8250_isa_devs Date: Fri, 4 Aug 2023 15:35:44 +0300 Message-ID: <20230804123546.25293-1-tony@atomide.com> X-Mailer: git-send-email 2.41.0 MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" After fixing the serial core port device to use port->port_id instead of port->line, unloading a hardware specific 8250 port driver started producing an error for "sysfs: cannot create duplicate filename". This is happening as we are wrongly initializing port->port_id to zero when adding back serial8250_isa_devs instances, and the serial8250:0.0 sysfs entry may already exist. For serial8250 devices, we typically have multiple devices mapped to a single driver instance. For the serial8250_isa_devs instances, the port->port_id is the same as port->line. Let's fix the issue by re-initializing port_id when adding back the serial8250_isa_devs instances in serial8250_unregister_port(). Fixes: d962de6ae51f ("serial: core: Fix serial core port id to not use port= ->line") Signed-off-by: Tony Lindgren Reviewed-by: Andy Shevchenko --- drivers/tty/serial/8250/8250_core.c | 1 + 1 file changed, 1 insertion(+) diff --git a/drivers/tty/serial/8250/8250_core.c b/drivers/tty/serial/8250/= 8250_core.c --- a/drivers/tty/serial/8250/8250_core.c +++ b/drivers/tty/serial/8250/8250_core.c @@ -1204,6 +1204,7 @@ void serial8250_unregister_port(int line) uart->port.flags &=3D ~UPF_BOOT_AUTOCONF; uart->port.type =3D PORT_UNKNOWN; uart->port.dev =3D &serial8250_isa_devs->dev; + uart->port.port_id =3D line; uart->capabilities =3D 0; serial8250_init_port(uart); serial8250_apply_quirks(uart); --=20 2.41.0