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 X-Spam-Level: X-Spam-Status: No, score=-4.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 51CFBC43461 for ; Sat, 5 Sep 2020 09:26:47 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0FE5B206A5 for ; Sat, 5 Sep 2020 09:26:47 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1599298007; bh=+ezArp0Mamo42Sub1yNL7kJYleMMNAOOe6LKTy4sgDA=; h=Date:From:To:Cc:Subject:In-Reply-To:References:List-ID:From; b=JIZo1yw+VDGtYRX+YzOFsHyKjbTJTDaVmi5PU2FnDp5nbZNwjtJGnIOgDhb8qo6hE aFH9mW2+xEVYUV0QPyldemF/SvA73ntLtuN43G6C/a2BB7OAm0C996forWkXd5dQH0 I6mQyBrYiBBOTbZ6sm6CGs6qrptlHbDrOistE5is= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728389AbgIEJ0q (ORCPT ); Sat, 5 Sep 2020 05:26:46 -0400 Received: from mail.kernel.org ([198.145.29.99]:40342 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728206AbgIEJ0p (ORCPT ); Sat, 5 Sep 2020 05:26:45 -0400 Received: from disco-boy.misterjones.org (disco-boy.misterjones.org [51.254.78.96]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id D6BA72074D; Sat, 5 Sep 2020 09:26:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1599298005; bh=+ezArp0Mamo42Sub1yNL7kJYleMMNAOOe6LKTy4sgDA=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=fENLhbl67GGyW+NF0HoaCKwXUKFlVytSUYB/S73xmr+joXH3DSAk9tOKaD6o3lQ+/ Ze/8Zlifu1te4Ri/q8GITddFkxykxTdzYP6h1PorVhsdN5zVL8/aujqI/VwdMdARhI nA+kUTxEjq8dtPmF5WQ6b9svgYDi69P8/KyXyrOI= Received: from 78.163-31-62.static.virginmediabusiness.co.uk ([62.31.163.78] helo=wait-a-minute.misterjones.org) by disco-boy.misterjones.org with esmtpsa (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1kEUT4-009LMf-No; Sat, 05 Sep 2020 10:26:42 +0100 Date: Sat, 05 Sep 2020 10:26:33 +0100 Message-ID: <878sdomv5i.wl-maz@kernel.org> From: Marc Zyngier To: Valentin Schneider Cc: linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, Jason Cooper , Thomas Gleixner , kernel-team@android.com Subject: Re: [PATCH v2 1/4] genirq: Walk the irq_data hierarchy when resending an interrupt In-Reply-To: References: <20200903183206.104838-1-maz@kernel.org> <20200903183206.104838-2-maz@kernel.org> User-Agent: Wanderlust/2.15.9 (Almost Unreal) SEMI-EPG/1.14.7 (Harue) FLIM/1.14.9 (=?UTF-8?B?R29qxY0=?=) APEL/10.8 EasyPG/1.0.0 Emacs/26.3 (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: 62.31.163.78 X-SA-Exim-Rcpt-To: valentin.schneider@arm.com, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, jason@lakedaemon.net, tglx@linutronix.de, kernel-team@android.com X-SA-Exim-Mail-From: maz@kernel.org X-SA-Exim-Scanned: No (on disco-boy.misterjones.org); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Valentin, On Fri, 04 Sep 2020 20:28:38 +0100, Valentin Schneider wrote: > > > Hi Marc, > > On 03/09/20 19:32, Marc Zyngier wrote: > > On resending an interrupt, we only check the topmost irqchip for > > a irq_retrigger callback. However, this callback could be implemented > > at a lower level. Use irq_chip_retrigger_hierarchy() in this case. > > > > Rookie wording question here; re-reading this I'm questioning which way is > up. > > From an irq_data hierarchy PoV, the topmost chip (i.e. last ->parent) > should be the root irqchip. However, the irq_desc we get from irq_to_desc() > ought to hold the irq_data for the lowermost irqchip in that irq_data > hierarchy. > > Is it that here by "topmost" you instead mean topmost of the irqchip stack > on top of the root (IOW furthest away from the root)? That's indeed what I mean, but I agree that the terminology is confusing, and often used inconsistently (by me included). Maybe considering the irqchip stack along a vertical axis is the wrong thing to do, and that looking at it as a volume would be marginally better? How about innermost (close to the CPU) vs outermost (close to the device)? Thanks, M. -- Without deviation from the norm, progress is not possible.