From mboxrd@z Thu Jan 1 00:00:00 1970 From: Yong Zhang Subject: Re: [RFC] [PATCH 02/62] mpu401:snd_mpu401_uart_new(): split semantic of irq_flags Date: Wed, 14 Sep 2011 16:49:57 +0800 Message-ID: <20110914084957.GB23710@zhy> 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> Reply-To: Yong Zhang Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Return-path: Content-Disposition: inline In-Reply-To: <4E6F2159.6060606@ladisch.de> Sender: linux-kernel-owner@vger.kernel.org To: Clemens Ladisch Cc: Takashi Iwai , linux-kernel@vger.kernel.org, Jaroslav Kysela , alsa-devel@alsa-project.org List-Id: alsa-devel@alsa-project.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