From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753595AbdLHWwC (ORCPT ); Fri, 8 Dec 2017 17:52:02 -0500 Received: from Galois.linutronix.de ([146.0.238.70]:57760 "EHLO Galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753339AbdLHWv6 (ORCPT ); Fri, 8 Dec 2017 17:51:58 -0500 Date: Fri, 8 Dec 2017 23:51:35 +0100 (CET) From: Thomas Gleixner To: =?ISO-8859-15?Q?Ville_Syrj=E4l=E4?= cc: "Augustine.Chen" , intel-gfx@lists.freedesktop.org, alsa-devel@alsa-project.org, jerome.anand@intel.com, pierre-louis.bossart@intel.com, tiwai@suse.de, Ingo Molnar , "H. Peter Anvin" , Jiang Liu , Juergen Gross , Dou Liyang , linux-kernel@vger.kernel.org Subject: Re: [Intel-gfx] [PATCH] drm/i915: Remove unused IRQ chip data of HDMI LPE audio In-Reply-To: <20171208114404.GN10981@intel.com> Message-ID: References: <20171208093323.2212-1-augustine.chen@intel.com> <20171208114404.GN10981@intel.com> User-Agent: Alpine 2.20 (DEB 67 2015-01-07) MIME-Version: 1.0 Content-Type: multipart/mixed; BOUNDARY="8323329-852617733-1512773495=:2301" X-Linutronix-Spam-Score: -1.0 X-Linutronix-Spam-Level: - X-Linutronix-Spam-Status: No , -1.0 points, 5.0 required, ALL_TRUSTED=-1,SHORTCIRCUIT=-0.0001 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This message is in MIME format. The first part should be readable text, while the remaining parts are likely unreadable without MIME-aware tools. --8323329-852617733-1512773495=:2301 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: 8BIT On Fri, 8 Dec 2017, Ville Syrjälä wrote: > On Fri, Dec 08, 2017 at 05:33:23PM +0800, Augustine.Chen wrote: > > The chip data of HDMI LPE audio is set to drm_i915_private which is not > > consistent with the expectation by x86 APIC driver. > > Hmm. Why is the apic code looking at data for an irq chip it > hasn't created? > > Do we need something like > - dev_priv->lpe_audio.irq = irq_alloc_desc(0); > + dev_priv->lpe_audio.irq = irq_alloc_desc(-1); #define irq_alloc_desc(node) So instead of handing in node 0 you hand in node -1 which is NUMA_NO_NODE > That *looks* more correct to me based on a cursory glance at the x86 > code, but I didn't trawl very deeply. The x86 core cares not at all about interrupt chips which are created in a driver and not connected to an actual apic/ioapic/msi interrupt. This interrupt chip is its own thing as we have others in GPIO etc. > > In the case of not enabling CONFIG_CPUMASK_OFFSTACK, this would cause > > kernel panic while doing CPU hotplug. And why so? Surely not because you set irq_chip_data. That's really no explanation at all. Curing the symptom is never a good approach. Thanks, tglx --8323329-852617733-1512773495=:2301--