From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755670Ab1IHXcq (ORCPT ); Thu, 8 Sep 2011 19:32:46 -0400 Received: from out4.smtp.messagingengine.com ([66.111.4.28]:55213 "EHLO out4.smtp.messagingengine.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754596Ab1IHXcl (ORCPT ); Thu, 8 Sep 2011 19:32:41 -0400 X-Sasl-enc: TZrjivTtowLg3w7FJjztErLYH2hbUv0hL9ZdriV4EPWg 1315513688 Message-ID: <4E69253F.3090705@ladisch.de> Date: Thu, 08 Sep 2011 22:27:43 +0200 From: Clemens Ladisch User-Agent: Thunderbird 2.0.0.23 (X11/20090820) MIME-Version: 1.0 To: Yong Zhang CC: linux-kernel@vger.kernel.org, tglx@linutronix.de, mingo@elte.hu, Jaroslav Kysela , Takashi Iwai , =?UTF-8?B?VXdlIEtsZWluZS1Lw7ZuaWc=?= , Jiri Kosina , Andreas Mohr , Lucas De Marchi , Julia Lawall , Ondrej Zary , Dan Carpenter , Joe Perches , alsa-devel@alsa-project.org Subject: Re: [RFC] [PATCH 02/62] mpu401:snd_mpu401_uart_new(): split semantic of irq_flags References: <1315383059-3673-1-git-send-email-yong.zhang0@gmail.com> <1315383059-3673-3-git-send-email-yong.zhang0@gmail.com> <4E689E9A.8000407@ladisch.de> <20110908133700.GB2310@zhy> <4E68CA15.8000504@ladisch.de> <20110908144519.GB3069@zhy> In-Reply-To: <20110908144519.GB3069@zhy> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Yong Zhang wrote: > On Thu, Sep 08, 2011 at 03:58:45PM +0200, Clemens Ladisch wrote: > > ... > > Here, "no interrupt" and "already reserved" actually mean the same thing, > > i.e., that the interrupt handling is the responsibility of some other > > driver. Sorry, after checking the code, I've realized that my description was wrong. irq_flags==0 ("already reserved") means that snd_mpu401_uart_new should not try to allocate the interrupt, while irq==-1 ("no interrupt") means that the device never issues mpu401 interrupts, so that the mpu401 code must use a timer to poll the device. I'll write a patch that changes this function so that irq<0 means "already reserved", and that "no interrupt" gets another bit in the info_flags parameter. Regards, Clemens From mboxrd@z Thu Jan 1 00:00:00 1970 From: Clemens Ladisch Subject: Re: [RFC] [PATCH 02/62] mpu401:snd_mpu401_uart_new(): split semantic of irq_flags Date: Thu, 08 Sep 2011 22:27:43 +0200 Message-ID: <4E69253F.3090705@ladisch.de> References: <1315383059-3673-1-git-send-email-yong.zhang0@gmail.com> <1315383059-3673-3-git-send-email-yong.zhang0@gmail.com> <4E689E9A.8000407@ladisch.de> <20110908133700.GB2310@zhy> <4E68CA15.8000504@ladisch.de> <20110908144519.GB3069@zhy> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from out4.smtp.messagingengine.com (out4.smtp.messagingengine.com [66.111.4.28]) by alsa0.perex.cz (Postfix) with ESMTP id E4DF724D55 for ; Thu, 8 Sep 2011 22:28:11 +0200 (CEST) In-Reply-To: <20110908144519.GB3069@zhy> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: alsa-devel-bounces@alsa-project.org Errors-To: alsa-devel-bounces@alsa-project.org To: Yong Zhang Cc: alsa-devel@alsa-project.org, Ondrej Zary , Dan Carpenter , Takashi Iwai , Jiri Kosina , linux-kernel@vger.kernel.org, Andreas Mohr , Lucas De Marchi , Julia Lawall , =?UTF-8?B?VXdlIEtsZWluZS1Lw7ZuaWc=?= , Joe Perches , tglx@linutronix.de, mingo@elte.hu List-Id: alsa-devel@alsa-project.org Yong Zhang wrote: > On Thu, Sep 08, 2011 at 03:58:45PM +0200, Clemens Ladisch wrote: > > ... > > Here, "no interrupt" and "already reserved" actually mean the same thing, > > i.e., that the interrupt handling is the responsibility of some other > > driver. Sorry, after checking the code, I've realized that my description was wrong. irq_flags==0 ("already reserved") means that snd_mpu401_uart_new should not try to allocate the interrupt, while irq==-1 ("no interrupt") means that the device never issues mpu401 interrupts, so that the mpu401 code must use a timer to poll the device. I'll write a patch that changes this function so that irq<0 means "already reserved", and that "no interrupt" gets another bit in the info_flags parameter. Regards, Clemens