Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754467AbaKSDlY (ORCPT ); Tue, 18 Nov 2014 22:41:24 -0500 Received: from szxga01-in.huawei.com ([119.145.14.64]:42416 "EHLO szxga01-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753796AbaKSDlX (ORCPT ); Tue, 18 Nov 2014 22:41:23 -0500 Message-ID: <546C1148.4080102@huawei.com> Date: Wed, 19 Nov 2014 11:40:56 +0800 From: "Yun Wu (Abel)" User-Agent: Mozilla/5.0 (Windows NT 6.1; rv:11.0) Gecko/20120327 Thunderbird/11.0.1 MIME-Version: 1.0 To: Marc Zyngier CC: Thomas Gleixner , Jiang Liu , LKML , "Bjorn Helgaas" , "grant.likely@linaro.org" , Yingjoe Chen , "Yijing Wang" Subject: Re: [patch 08/16] genirq: Introduce callback irq_chip.irq_write_msi_msg References: <20141112133941.647950773@linutronix.de> <20141112134120.474411359@linutronix.de> <546B10DF.7020807@huawei.com> <546B4A91.6080004@huawei.com> <546B4D0D.9050601@linux.intel.com> <546B4F18.5060705@huawei.com> <546B5904.6020200@huawei.com> <8761ece85x.fsf@approximate.cambridge.arm.com> In-Reply-To: <8761ece85x.fsf@approximate.cambridge.arm.com> Content-Type: text/plain; charset="ISO-8859-1" Content-Transfer-Encoding: 7bit X-Originating-IP: [10.177.24.136] X-CFilter-Loop: Reflected Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2014/11/19 1:21, Marc Zyngier wrote: > On Tue, Nov 18 2014 at 2:34:44 pm GMT, "Yun Wu (Abel)" wrote: >> On 2014/11/18 22:19, Thomas Gleixner wrote: >> >>> On Tue, 18 Nov 2014, Yun Wu (Abel) wrote: >>>> On 2014/11/18 21:43, Jiang Liu wrote: >>>>> We provide an irq_chip for each type of interrupt controller >>>>> instead of devices. For the example mentioned above, if device A >>>>> and Group B has different interrupt controllers, we just need to >>>>> implement irq_chip_A and irq_chip_B and set irq_chip.irq_write_msi_msg() >>>>> to suitable callbacks. >>>>> The framework already achieves what you you want:) >>>> >>>> What if device A and group B have the same interrupt controller? >>> >>> Well, if write_msg() is different they are hardly the same. >>> >> >> The GICv3 ITS now deals with both PCI and non PCI message interrupts. >> We can't require the new devices behave writing message in a same way. >> What we can do is to abstract all the endpoints' behavior, and I >> provided one abstraction in an earlier reply. > > This is why the framework gives you the opportunity to provide methods > that: > - compose the message > - program the message into the device > > None of that has to be PCI specific, and gives you a clean > abstraction. The framework only gives you a number of shortcuts for PCI > MSI, because that's what most people care about. > Indeed, and I never said Jiang's patches don't work, I was just thinking that they were not that perfect. Thanks, Abel -- 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/