From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754737Ab1INIz2 (ORCPT ); Wed, 14 Sep 2011 04:55:28 -0400 Received: from mail-wy0-f180.google.com ([74.125.82.180]:41101 "EHLO mail-wy0-f180.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754291Ab1INIz1 (ORCPT ); Wed, 14 Sep 2011 04:55:27 -0400 X-Greylist: delayed 319 seconds by postgrey-1.27 at vger.kernel.org; Wed, 14 Sep 2011 04:55:27 EDT Date: Wed, 14 Sep 2011 16:49:57 +0800 From: Yong Zhang To: Clemens Ladisch Cc: Takashi Iwai , linux-kernel@vger.kernel.org, Jaroslav Kysela , alsa-devel@alsa-project.org Subject: Re: [RFC] [PATCH 02/62] mpu401:snd_mpu401_uart_new(): split semantic of irq_flags Message-ID: <20110914084957.GB23710@zhy> Reply-To: Yong Zhang References: <20110908144519.GB3069@zhy> <4E69253F.3090705@ladisch.de> <20110909013143.GB18249@zhy> <4E6CCF6C.2020301@ladisch.de> <4E6E061E.2010000@ladisch.de> <4E6E6A34.8060104@ladisch.de> <4E6F1194.80106@ladisch.de> <4E6F2159.6060606@ladisch.de> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <4E6F2159.6060606@ladisch.de> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Sep 13, 2011 at 11:24:41AM +0200, Clemens Ladisch wrote: [snip] > > completely untested: > > --8<---------------------------------------------------------------->8-- > ALSA: mpu401: clean up interrupt specification > > The semantics of snd_mpu401_uart_new()'s interrupt parameters are > somewhat counterintuitive: To prevent the function from allocating its > own interrupt, either the irq number must be invalid, or the irq_flags > parameter must be zero. At the same time, the irq parameter being > invalid specifies that the mpu401 code has to work without an interrupt > allocated by the caller. This implies that, if there is an interrupt > and it is allocated by the caller, the irq parameter must be set to > a valid-looking number which then isn't actually used. > > With the removal of IRQF_DISABLED, zero becomes a valid irq_flags value, > which forces us to handle the parameters differently. > > This patch introduces a new flag MPU401_INFO_IRQ_HOOK for when the > device interrupt is handled by the caller, and makes the allocation of > the interrupt to depend only on the irq parameter. As suggested by > Takashi, the irq_flags parameter was dropped because, when used, it had > the constant value IRQF_DISABLED. Thanks Clemens. Your patch will eventually save much lines from mine , actually I only need to touch request_irq() in snd_mpu401_uart_new(). But do you have any idea by which tree this patch will go to mainline? Thus I could make a new patch based on it :) Thanks, Yong > > Signed-off-by: Clemens Ladisch