From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 6C5B0C6FA86 for ; Sat, 10 Sep 2022 14:40:51 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229626AbiIJOkt (ORCPT ); Sat, 10 Sep 2022 10:40:49 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50264 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229531AbiIJOkr (ORCPT ); Sat, 10 Sep 2022 10:40:47 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3CE332714F; Sat, 10 Sep 2022 07:40:33 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 7B72360CD4; Sat, 10 Sep 2022 14:40:32 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id C71C9C433D6; Sat, 10 Sep 2022 14:40:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1662820831; bh=yoLyrhPTFTvBgeQMrdTZ1aOP2pxInq6DJu6Ae8eysg0=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=kdpA6DJoqSDG8On3+fYzAcvlQQH2ovwvFFRtWCSP4W+O8kTwr3A9aTM2+JjrMoL2t qECi7WfNNOgG7gv4KzTvbJgFCg8xD25AOdw7O79YuHJWT9yods0zdEVcL5ZgHO1CB5 To2sUNaMW9MHLarY7xtVShKufm1NFFNTa4y+rMMRxzWfOXNx2mrJtOCiCrpMaTSQZT BnuFtfNkYD2aJOVZNBH59LcJ9b/9ZHl+FNzTH1Y3JBcywMKeCnZHmFJ8zfcYxsTw/k N618MBrj+mCMUMBKRZTgStS6O7Kbh0zMLMFzKjdILtXldKY2iMPJ32j/ghIMew+MF7 o8rmoprpbiWlw== Received: from sofa.misterjones.org ([185.219.108.64] helo=wait-a-minute.misterjones.org) by disco-boy.misterjones.org with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.95) (envelope-from ) id 1oX1en-009Pak-He; Sat, 10 Sep 2022 15:40:29 +0100 Date: Sat, 10 Sep 2022 15:40:29 +0100 Message-ID: <87wnabpa1u.wl-maz@kernel.org> From: Marc Zyngier To: Frank Li Cc: "tglx@linutronix.de" , "robh+dt@kernel.org" , "krzysztof.kozlowski+dt@linaro.org" , "shawnguo@kernel.org" , "s.hauer@pengutronix.de" , "kw@linux.com" , "bhelgaas@google.com" , "linux-kernel@vger.kernel.org" , "devicetree@vger.kernel.org" , "linux-arm-kernel@lists.infradead.org" , "linux-pci@vger.kernel.org" , Peng Fan , Aisheng Dong , "jdmason@kudzu.us" , "kernel@pengutronix.de" , "festevam@gmail.com" , dl-linux-imx , "kishon@ti.com" , "lorenzo.pieralisi@arm.com" , "ntb@lists.linux.dev" , "lznuaa@gmail.com" , "imx@lists.linux.dev" , "manivannan.sadhasivam@linaro.org" Subject: Re: [EXT] Re: [PATCH v9 2/4] irqchip: Add IMX MU MSI controller driver In-Reply-To: References: <20220907034856.3101570-1-Frank.Li@nxp.com> <20220907034856.3101570-3-Frank.Li@nxp.com> <87fsh2qpq4.wl-maz@kernel.org> User-Agent: Wanderlust/2.15.9 (Almost Unreal) SEMI-EPG/1.14.7 (Harue) FLIM-LB/1.14.9 (=?UTF-8?B?R29qxY0=?=) APEL-LB/10.8 EasyPG/1.0.0 Emacs/27.1 (x86_64-pc-linux-gnu) MULE/6.0 (HANACHIRUSATO) MIME-Version: 1.0 (generated by SEMI-EPG 1.14.7 - "Harue") Content-Type: text/plain; charset=US-ASCII X-SA-Exim-Connect-IP: 185.219.108.64 X-SA-Exim-Rcpt-To: frank.li@nxp.com, tglx@linutronix.de, robh+dt@kernel.org, krzysztof.kozlowski+dt@linaro.org, shawnguo@kernel.org, s.hauer@pengutronix.de, kw@linux.com, bhelgaas@google.com, linux-kernel@vger.kernel.org, devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-pci@vger.kernel.org, peng.fan@nxp.com, aisheng.dong@nxp.com, jdmason@kudzu.us, kernel@pengutronix.de, festevam@gmail.com, linux-imx@nxp.com, kishon@ti.com, lorenzo.pieralisi@arm.com, ntb@lists.linux.dev, lznuaa@gmail.com, imx@lists.linux.dev, manivannan.sadhasivam@linaro.org X-SA-Exim-Mail-From: maz@kernel.org X-SA-Exim-Scanned: No (on disco-boy.misterjones.org); SAEximRunCond expanded to false Precedence: bulk List-ID: X-Mailing-List: devicetree@vger.kernel.org On Fri, 09 Sep 2022 15:52:45 +0100, Frank Li wrote: > > > > + select IRQ_DOMAIN > > > + select IRQ_DOMAIN_HIERARCHY > > > + select GENERIC_MSI_IRQ_DOMAIN > > > + help > > > + MU work as MSI controller to do general doorbell > > > > I'm not sure this is that generic. It really is limited to CPU-to-CPU > > interrupts. > > [Frank Li] I think the only limitation is only 4 irq numbers. > The principle CPU to CPU irq is the same as MSI. Not quite. Normal MSIs are device-to-CPU. CPU-to-CPU are normally IPIs, and this one falls in the middle. > What's your preferred help description? Provide a driver for the MU block used as a CPU-to-CPU MSI controller. This requires a specially crafted DT to make use of this driver. If unsure, say N. M. -- Without deviation from the norm, progress is not possible.