From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Mon, 5 Nov 2001 17:57:12 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Mon, 5 Nov 2001 17:57:03 -0500 Received: from inetc.connecttech.com ([64.7.140.42]:18186 "EHLO inetc.connecttech.com") by vger.kernel.org with ESMTP id ; Mon, 5 Nov 2001 17:56:51 -0500 Message-ID: <054801c1664d$8bc8eb80$294b82ce@connecttech.com> From: "Stuart MacDonald" To: Subject: [Patch] Serial lockup fixed Date: Mon, 5 Nov 2001 17:59:38 -0500 Organization: Connect Tech Inc. X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 5.50.4807.1700 X-MimeOLE: Produced By Microsoft MimeOLE V5.50.4807.1700 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org After installing any serial-5.00 or later in kernels 2.2.18, 19 or 20, rs_init is entered twice. This results in the serial timer being added twice, which corrupts the timer list and causes an infinite loop. The symptom is a complete hang on boot, usually just after the "Freeing unused kernel memory" message. Pre 18 the call path is do_basic_setup() -> device_setup() -> chr_dev_setup() -> tty_init() -> rs_init(). In 2.4.x rs_init is entered with the module_init() (__initcall) magic. The attached is for 2.2.20, and simply removes the tty_init() -> rs_init() path. This mimics 2.4.x. There might be an issue; do_initcalls() is slightly later in do_basic_setup() than device_setup(), but the in between code looks similar to 2.4.x kernels so I don't think it's a problem delaying the serial init. I'll post the slightly less elegant hack to the serial driver that compensates for the broken kernels shortly. Patch status is: Works For Me. Testers needed. ..Stu ---- diff -ru linux-2.2.20/drivers/char/tty_io.c linux-2.2.20-serial-init-fix/drivers/char/tty_io.c --- linux-2.2.20/drivers/char/tty_io.c Fri Nov 2 11:39:06 2001 +++ linux-2.2.20-serial-init-fix/drivers/char/tty_io.c Mon Nov 5 22:03:54 2001 @@ -2189,9 +2189,6 @@ #ifdef CONFIG_ESPSERIAL /* init ESP before rs, so rs doesn't see the port */ espserial_init(); #endif -#ifdef CONFIG_SERIAL - rs_init(); -#endif #ifdef CONFIG_COMPUTONE ip2_init(); #endif