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=-5.5 required=3.0 tests=BAYES_00,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 B51B9C433E6 for ; Mon, 1 Feb 2021 19:55:11 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 63E6D64ECA for ; Mon, 1 Feb 2021 19:55:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232326AbhBATzC (ORCPT ); Mon, 1 Feb 2021 14:55:02 -0500 Received: from mail-wr1-f48.google.com ([209.85.221.48]:32969 "EHLO mail-wr1-f48.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232713AbhBATyX (ORCPT ); Mon, 1 Feb 2021 14:54:23 -0500 Received: by mail-wr1-f48.google.com with SMTP id 7so17991980wrz.0; Mon, 01 Feb 2021 11:53:55 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to:user-agent; bh=DCjhNmegL5cty51UJJiVLzoT3IZRsyqfK3odFUkK4z8=; b=FIi09leopkGtYp/mCaSB3wIWcGzgubDYzeDJOUAbNMa2o8QfR/GV0TyV1UsF0Gk/st PDkVAJYh6QSvYSfJI3SnupXQa5XaaOi1wt4e03hB3g89h6dvWEkhUwMW2jy8rgDSs+VW lobi4qkQHLpndY6OgXFisutCfHDTCnR+yR6UyaNJnEjJ0CIRlbWteD165ijILNmVBEnd 6smpxioO0d9YmbAYnKhB195hP9vYaeLlLYOX+kq1hDBxn2zPF7ug3u5kzs76CS+/1N7v MojKGwocRdXOxCINO5IjbDQGDBzk4k68455qvkoH97v9/xWDggMyemQe7dwJaQj1pMPT 826Q== X-Gm-Message-State: AOAM533Dwak9x3csQIywrzmUiy8lH8LVHGZNF1UVUHtiyN3IizWHIAER WSVPNsOes4i84g8txbMNQ5c= X-Google-Smtp-Source: ABdhPJww1TvLldgLGFf0r7SZNri+3W5aYbD06nxT/kZ6LKQbZOATXExXYWTbE0ltqdgS/HE8QDXArg== X-Received: by 2002:adf:a11d:: with SMTP id o29mr20016981wro.45.1612209209605; Mon, 01 Feb 2021 11:53:29 -0800 (PST) Received: from liuwe-devbox-debian-v2 ([51.145.34.42]) by smtp.gmail.com with ESMTPSA id y6sm328678wma.19.2021.02.01.11.53.29 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 01 Feb 2021 11:53:29 -0800 (PST) Date: Mon, 1 Feb 2021 19:53:27 +0000 From: Wei Liu To: Michael Kelley Cc: sthemmin@microsoft.com, kys@microsoft.com, wei.liu@kernel.org, tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, hpa@zytor.com, daniel.lezcano@linaro.org, arnd@arndb.de, linux-hyperv@vger.kernel.org, linux-kernel@vger.kernel.org, x86@kernel.org, linux-arch@vger.kernel.org Subject: Re: [PATCH 10/10] clocksource/drivers/hyper-v: Move handling of STIMER0 interrupts Message-ID: <20210201195327.2bkhu6sig53prwwg@liuwe-devbox-debian-v2> References: <1611779025-21503-1-git-send-email-mikelley@microsoft.com> <1611779025-21503-11-git-send-email-mikelley@microsoft.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1611779025-21503-11-git-send-email-mikelley@microsoft.com> User-Agent: NeoMutt/20180716 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Jan 27, 2021 at 12:23:45PM -0800, Michael Kelley wrote: [...] > +static int hv_setup_stimer0_irq(void) > +{ > + int ret; > + > + ret = acpi_register_gsi(NULL, HYPERV_STIMER0_VECTOR, > + ACPI_EDGE_SENSITIVE, ACPI_ACTIVE_HIGH); When IO-APIC is enabled on x86, acpi_register_gsi calls mp_map_gsi_to_irq. That function then calls mp_find_ioapic. Is HYPERV_STIMER0_VECTOR, when used as a GSI, associated with an IO-APIC? If not, wouldn't mp_find_ioapic return an error causing acpi_register_gsi to fail? Ah, it appears that this function is not called on x86. I haven't checked how ARM handles GSI, but presumably this works for you. It would be good if a comment can be added to clarify things. Wei.