From patchwork Thu Apr 13 07:03:41 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Tony Lindgren X-Patchwork-Id: 82832 Return-Path: Delivered-To: ouuuleilei@gmail.com Received: by 2002:a59:b0ea:0:b0:3b6:4342:cba0 with SMTP id b10csp842918vqo; Thu, 13 Apr 2023 00:13:38 -0700 (PDT) X-Google-Smtp-Source: AKy350YJrbnP5OCyCp5w6DY3j/7eErsoSwB5u6vHP/oTMAEMLTvqCfA4OknozGd3oH/TYwUgSIv7 X-Received: by 2002:aa7:c2d4:0:b0:504:923f:e657 with SMTP id m20-20020aa7c2d4000000b00504923fe657mr1519359edp.35.1681370018386; Thu, 13 Apr 2023 00:13:38 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1681370018; cv=none; d=google.com; s=arc-20160816; b=0CxBrz0cEICvxERp5wU6h5skhvCeLb3Iv3Ae+uOJKKXR2vr8ZYU81Q84bvJpxDU095 /VS63xwFVhEUqU1x3aenouwBYb5v99lcxfPhvSIN/VIMosbU+B+hOXTArxQdG/9TkLfg 393iQQYls82NQmhsS/MXNZxlWWQ5yFHcqIZEID7JdyUOtm0rNujLSWZAchSo0Qcr8Oo0 ZEse+ZK+9Uo0wHi0tcJJR3N6QW7ZD4Me1iCYXHutSjhOUGWnM/dLAgh+pqGhZC8Wt1TQ 9FSJ3fJHmpkPhQbJoCvPBr+ikx0KEfoc1DUFehjH7s2kRzQj4f95GxT0ruDItlIFHdB0 Dngw== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:content-transfer-encoding:mime-version :message-id:date:subject:cc:to:from; bh=SHwJBrq4SwRDMeu2g/n7MDDNulLRu/ved3hljXaXi5k=; b=Jqg7H6wW7NVtOTjT6riIgXtu2MzpBtSy04HtI5/O5K/oC7zAvbcSomu9VoEHhf+G05 riophuaRT/QAgPuLsxXaBVeKVIShdZ1p+oiKEc+pHmjWaxIo2K3OePsQPcrJtqnehRsD qF3Hm/W33/OvgXrfkzEk+cd4wbqMJPWRWWNpi6KuTV1CGicS5G76lM4Zve25ATli6T20 lFyADwT3kXQEu5CIqhmZ1aHIbqMyvCW/myr5so2mzSMarqn2jwKrINM9q3pG17hXt23c FMcm+IM0l3ZjJITQysL47Sxn9nAX/knfnAH69ffye6B/2MqIFmm0Rx8hLMWCXrnP7gaB RTDQ== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: from out1.vger.email (out1.vger.email. [2620:137:e000::1:20]) by mx.google.com with ESMTP id c13-20020aa7df0d000000b00504806b0ff0si1125136edy.127.2023.04.13.00.13.14; Thu, 13 Apr 2023 00:13:38 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20; Authentication-Results: mx.google.com; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229721AbjDMHEB (ORCPT + 99 others); Thu, 13 Apr 2023 03:04:01 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57838 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229599AbjDMHD5 (ORCPT ); Thu, 13 Apr 2023 03:03:57 -0400 Received: from muru.com (muru.com [72.249.23.125]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 5344F46B9; Thu, 13 Apr 2023 00:03:56 -0700 (PDT) Received: from hillo.muru.com (localhost [127.0.0.1]) by muru.com (Postfix) with ESMTP id 5C3C580F0; Thu, 13 Apr 2023 07:03:54 +0000 (UTC) From: Tony Lindgren To: Greg Kroah-Hartman , Jiri Slaby Cc: Andy Shevchenko , =?utf-8?q?Ilpo_J=C3=A4rvi?= =?utf-8?q?nen?= , Johan Hovold , Sebastian Andrzej Siewior , Vignesh Raghavendra , linux-omap@vger.kernel.org, linux-serial@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH] serial: 8250: Clear port->pm on port specific driver unbind Date: Thu, 13 Apr 2023 10:03:41 +0300 Message-Id: <20230413070342.36155-1-tony@atomide.com> X-Mailer: git-send-email 2.40.0 MIME-Version: 1.0 X-Spam-Status: No, score=-1.9 required=5.0 tests=BAYES_00,SPF_HELO_NONE, SPF_NONE,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org X-getmail-retrieved-from-mailbox: =?utf-8?q?INBOX?= X-GMAIL-THRID: =?utf-8?q?1763044248634019753?= X-GMAIL-MSGID: =?utf-8?q?1763044248634019753?= When we unbind a serial port hardware specific 8250 driver, the generic serial8250 driver takes over the port. After that we see an oops about 10 seconds later. This can produce the following at least on some TI SoCs: Unhandled fault: imprecise external abort (0x1406) Internal error: : 1406 [#1] SMP ARM Turns out that we may still have the serial port hardware specific driver port->pm in use, and serial8250_pm() tries to call it after the port specific driver is gone: serial8250_pm [8250_base] from uart_change_pm+0x54/0x8c [serial_base] uart_change_pm [serial_base] from uart_hangup+0x154/0x198 [serial_base] uart_hangup [serial_base] from __tty_hangup.part.0+0x328/0x37c __tty_hangup.part.0 from disassociate_ctty+0x154/0x20c disassociate_ctty from do_exit+0x744/0xaac do_exit from do_group_exit+0x40/0x8c do_group_exit from __wake_up_parent+0x0/0x1c Let's fix the issue by clearing port->pm in serial8250_unregister_port(). Signed-off-by: Tony Lindgren Reviewed-by: Andy Shevchenko Reviewed-by: Ilpo Järvinen --- 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 @@ -1157,6 +1157,7 @@ void serial8250_unregister_port(int line) uart->port.flags &= ~UPF_BOOT_AUTOCONF; uart->port.type = PORT_UNKNOWN; uart->port.dev = &serial8250_isa_devs->dev; + uart->port.pm = NULL; uart->capabilities = 0; serial8250_apply_quirks(uart); uart_add_one_port(&serial8250_reg, &uart->port);