From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754739AbeDTMK7 (ORCPT ); Fri, 20 Apr 2018 08:10:59 -0400 Received: from mx2.suse.de ([195.135.220.15]:44366 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754607AbeDTMK5 (ORCPT ); Fri, 20 Apr 2018 08:10:57 -0400 Date: Fri, 20 Apr 2018 14:10:54 +0200 Message-ID: From: Takashi Iwai To: Kai-Heng Feng Cc: mjg59@srcf.ucam.org, pali.rohar@gmail.com, dvhart@infradead.org, andy@infradead.org, mario.limonciello@dell.com, tiwai@suse.com, alsa-devel@alsa-project.org, linux-kernel@vger.kernel.org, platform-driver-x86@vger.kernel.org Subject: Re: [alsa-devel] [PATCH v4 3/3] ALSA: hda: Disabled unused audio controller for Dell platforms with Switchable Graphics In-Reply-To: <20180420094432.13133-3-kai.heng.feng@canonical.com> References: <20180420094432.13133-1-kai.heng.feng@canonical.com> <20180420094432.13133-3-kai.heng.feng@canonical.com> User-Agent: Wanderlust/2.15.9 (Almost Unreal) SEMI/1.14.6 (Maruoka) FLIM/1.14.9 (=?UTF-8?B?R29qxY0=?=) APEL/10.8 Emacs/25.3 (x86_64-suse-linux-gnu) MULE/6.0 (HANACHIRUSATO) MIME-Version: 1.0 (generated by SEMI 1.14.6 - "Maruoka") Content-Type: text/plain; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, 20 Apr 2018 11:44:32 +0200, Kai-Heng Feng wrote: > > Now it's a typical discrete-only system. HDMI audio comes from AMD audio > controller, others from Intel audio controller. > > When SG is enabled, the unused AMD audio contoller still exposes its > sysfs, so userspace still opens the control file and stream. If > userspace tries to output sound through the stream, it hangs the system. Hm, could you give more information about how it hangs? > @@ -1627,6 +1629,42 @@ static void check_msi(struct azx *chip) > } > } > > +#if IS_ENABLED(CONFIG_DELL_LAPTOP) This should be IS_REACHABLE(), as both dell-laptop and HD-audio are tristate. > +static bool check_dell_switchable_gfx(struct pci_dev *pdev) I'd remove "_dell" word here. Such a check would be likely needed for other vendors, and it's quite possible that the function will be extended to cover a wider DMI table. thanks, Takashi