Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Thu, 28 Feb 2002 04:34:28 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Thu, 28 Feb 2002 04:32:18 -0500 Received: from bs1.dnx.de ([213.252.143.130]:15261 "EHLO bs1.dnx.de") by vger.kernel.org with ESMTP id ; Thu, 28 Feb 2002 04:30:03 -0500 Date: Thu, 28 Feb 2002 10:29:17 +0100 (CET) From: Robert Schwebel X-X-Sender: Reply-To: To: Alan Cox Cc: Dave Jones , Marcelo Tosatti , Linux Kernel List Subject: [PATCH] Serial driver patch for AMD Elans Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Below you'll find the part of the AMD Elan patch which deals with a bug in the processor-integrated serial interface. The code was discussed with Theodore Ts'o and Russell King - tytso wanted to send it to Marcelo afterwards, but nothing happened so far, so here's the patch, against 2.4.18. Thx, Robert -- +--------------------------------------------------------+ | Dipl.-Ing. Robert Schwebel | http://www.pengutronix.de | | Pengutronix - Linux Solutions for Science and Industry | | Braunschweiger Str. 79, 31134 Hildesheim, Germany | | Phone: +49-5121-28619-0 | Fax: +49-5121-28619-4 | +--------------------------------------------------------+ diff -urN -X kernel-patches/dontdiff linux-2.4.18/drivers/char/serial.c linux-2.4.18-elan/drivers/char/serial.c --- linux-2.4.18/drivers/char/serial.c Mon Feb 25 20:37:57 2002 +++ linux-2.4.18-elan/drivers/char/serial.c Tue Feb 26 09:58:39 2002 @@ -57,6 +57,11 @@ * 10/00: add in optional software flow control for serial console. * Kanoj Sarcar (Modified by Theodore Ts'o) * + * 02/02: Fix for AMD Elan bug in transmit irq routine, by + * Christer Weinigel , + * Robert Schwebel , + * Juergen Beisert , + * Theodore Ts'o */ static char *serial_version = "5.05c"; @@ -801,7 +806,7 @@ */ static void rs_interrupt(int irq, void *dev_id, struct pt_regs * regs) { - int status; + int status, iir; struct async_struct * info; int pass_counter = 0; struct async_struct *end_mark = 0; @@ -826,7 +831,7 @@ do { if (!info->tty || - (serial_in(info, UART_IIR) & UART_IIR_NO_INT)) { + ((iir=serial_in(info, UART_IIR)) & UART_IIR_NO_INT)) { if (!end_mark) end_mark = info; goto next; @@ -845,7 +850,9 @@ if (status & UART_LSR_DR) receive_chars(info, &status, regs); check_modem_status(info); - if (status & UART_LSR_THRE) + if ((status & UART_LSR_THRE) || + /* for buggy ELAN processors */ + ((iir & UART_IIR_ID) == UART_IIR_THRI)) transmit_chars(info, 0); next: @@ -879,7 +886,7 @@ */ static void rs_interrupt_single(int irq, void *dev_id, struct pt_regs * regs) { - int status; + int status, iir; int pass_counter = 0; struct async_struct * info; #ifdef CONFIG_SERIAL_MULTIPORT @@ -901,6 +908,7 @@ first_multi = inb(multi->port_monitor); #endif + iir = serial_in(info, UART_IIR); do { status = serial_inp(info, UART_LSR); #ifdef SERIAL_DEBUG_INTR @@ -909,18 +917,21 @@ if (status & UART_LSR_DR) receive_chars(info, &status, regs); check_modem_status(info); - if (status & UART_LSR_THRE) + if ((status & UART_LSR_THRE) || + /* For buggy ELAN processors */ + ((iir & UART_IIR_ID) == UART_IIR_THRI)) transmit_chars(info, 0); if (pass_counter++ > RS_ISR_PASS_LIMIT) { -#if 0 +#if SERIAL_DEBUG_INTR printk("rs_single loop break.\n"); #endif break; } + iir = serial_in(info, UART_IIR); #ifdef SERIAL_DEBUG_INTR - printk("IIR = %x...", serial_in(info, UART_IIR)); + printk("IIR = %x...", iir); #endif - } while (!(serial_in(info, UART_IIR) & UART_IIR_NO_INT)); + } while ((iir & UART_IIR_NO_INT) == 0); info->last_active = jiffies; #ifdef CONFIG_SERIAL_MULTIPORT if (multi->port_monitor) - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/