From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1750806AbWDRNSE (ORCPT ); Tue, 18 Apr 2006 09:18:04 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1750891AbWDRNSE (ORCPT ); Tue, 18 Apr 2006 09:18:04 -0400 Received: from mail.suse.de ([195.135.220.2]:58827 "EHLO mx1.suse.de") by vger.kernel.org with ESMTP id S1750806AbWDRNSC (ORCPT ); Tue, 18 Apr 2006 09:18:02 -0400 Date: Tue, 18 Apr 2006 15:18:01 +0200 Message-ID: From: Takashi Iwai To: Jon Masters Cc: akpm@osdl.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] sound: fix hang in mpu401_uart.c In-Reply-To: <20060416031235.GA6741@apogee.jonmasters.org> References: <20060416031235.GA6741@apogee.jonmasters.org> User-Agent: Wanderlust/2.12.0 (Your Wildest Dreams) SEMI/1.14.6 (Maruoka) FLIM/1.14.7 (=?ISO-8859-4?Q?Sanj=F2?=) APEL/10.6 MULE XEmacs/21.5 (beta25) (eggplant) (+CVS-20060326) (i386-suse-linux) MIME-Version: 1.0 (generated by SEMI 1.14.6 - "Maruoka") Content-Type: text/plain; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org At Sun, 16 Apr 2006 04:12:36 +0100, Jon Masters wrote: > > From: Jon Masters > > This fixes a hang in mpu401_uart.c that can occur when the mpu401 > interface is non-existent or otherwise doesn't respond to commands but > we issue IO anyway. snd_mpu401_uart_cmd now returns an error code that is > passed up the stack so that an open() will fail immediately in such cases. > > Eventually discovered after wine/cxoffice would constantly cause hard > lockups on my desktop immediately after loading (emulating Windows too > well). Turned out that I'd recently moved my sound cards around and > using /dev/sequencer now talks to a sound card with a broken MPU. > > Signed-off-by: Jon Masters (snip) > @@ -235,8 +238,12 @@ > if (mpu->open_input && (err = mpu->open_input(mpu)) < 0) > return err; > if (! test_bit(MPU401_MODE_BIT_OUTPUT, &mpu->mode)) { > - snd_mpu401_uart_cmd(mpu, MPU401_RESET, 1); > - snd_mpu401_uart_cmd(mpu, MPU401_ENTER_UART, 1); > + if ((err = snd_mpu401_uart_cmd(mpu, MPU401_RESET, 1))) { > + return -EFAULT; IMO, -EFAULT isn't a good choice for this kind of error. > @@ -252,8 +259,10 @@ > if (mpu->open_output && (err = mpu->open_output(mpu)) < 0) > return err; > if (! test_bit(MPU401_MODE_BIT_INPUT, &mpu->mode)) { > - snd_mpu401_uart_cmd(mpu, MPU401_RESET, 1); > - snd_mpu401_uart_cmd(mpu, MPU401_ENTER_UART, 1); > + if ((err = snd_mpu401_uart_cmd(mpu, MPU401_RESET, 1))) > + return -EFAULT; > + if ((err = snd_mpu401_uart_cmd(mpu, MPU401_ENTER_UART, 1))) > + return -EFAULT; Missing close in the error path? Takashi