From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752432AbeDLKuH (ORCPT ); Thu, 12 Apr 2018 06:50:07 -0400 Received: from mx2.suse.de ([195.135.220.15]:44393 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751112AbeDLKuF (ORCPT ); Thu, 12 Apr 2018 06:50:05 -0400 Date: Thu, 12 Apr 2018 12:50:02 +0200 Message-ID: From: Takashi Iwai To: "Kai-Heng Feng" Cc: Lukas Wunner , , , , , , , , Subject: Re: [PATCH v3 3/3] ALSA: hda: Disabled unused audio controller for Dell platforms with Switchable Graphics In-Reply-To: <20180412104239.25584-3-kai.heng.feng@canonical.com> References: <20180412104239.25584-1-kai.heng.feng@canonical.com> <20180412104239.25584-3-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 Thu, 12 Apr 2018 12:42:39 +0200, Kai-Heng Feng wrote: > > Some Dell platforms (Preicsion 7510/7710/7520/7720) have a BIOS option > "Switchable Graphics" (SG). > > When SG is enabled, we have: > 00:02.0 VGA compatible controller: Intel Corporation Device 591b (rev 04) > 00:1f.3 Audio device: Intel Corporation CM238 HD Audio Controller (rev 31) > 01:00.0 VGA compatible controller: Advanced Micro Devices, Inc. [AMD/ATI] Ellesmere [Polaris10] > 01:00.1 Audio device: Advanced Micro Devices, Inc. [AMD/ATI] Ellesmere [Radeon RX 580] > > The Intel Audio outputs all the sound, including HDMI audio. The audio > controller comes with AMD graphics doesn't get used. > > When SG is disabled, we have: > 00:1f.3 Audio device: Intel Corporation CM238 HD Audio Controller (rev 31) > 01:00.0 VGA compatible controller: Advanced Micro Devices, Inc. [AMD/ATI] Ellesmere [Polaris10] > 01:00.1 Audio device: Advanced Micro Devices, Inc. [AMD/ATI] Ellesmere [Radeon RX 580] > > 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 controller still exposes its > sysfs, so userspace still opens the control file and stream. If > userspace tries to output sound through the stream, it hangs when > runtime suspend kicks in: > [ 12.796265] snd_hda_intel 0000:01:00.1: Disabling via vga_switcheroo > [ 12.796367] snd_hda_intel 0000:01:00.1: Cannot lock devices! > > Since the discrete audio controller isn't useful when SG enabled, we > should just disable the device. > > Signed-off-by: Kai-Heng Feng Adding Lukas to Cc. I thought we manage this better now with runtime PM by Lukas's recent patchset? thanks, Takashi > --- > v3: Simplify dell_switchable_gfx_is_enabled() by returning bool instead > of error code. > Use DMI_DEV_TYPE_OEM_STRING to match Dell System. > > v2: Mario suggested to squash the HDA part into the same series. > > sound/pci/hda/hda_intel.c | 39 +++++++++++++++++++++++++++++++++++++++ > 1 file changed, 39 insertions(+) > > diff --git a/sound/pci/hda/hda_intel.c b/sound/pci/hda/hda_intel.c > index 7720e3102bcc..d9310616d5ca 100644 > --- a/sound/pci/hda/hda_intel.c > +++ b/sound/pci/hda/hda_intel.c > @@ -49,6 +49,8 @@ > #include > #include > #include > +#include > +#include > > #ifdef CONFIG_X86 > /* for snoop control */ > @@ -1629,6 +1631,38 @@ static void check_msi(struct azx *chip) > } > } > > +#if IS_ENABLED(CONFIG_DELL_LAPTOP) > +static bool check_dell_switchable_gfx(struct pci_dev *pdev) > +{ > + bool (*dell_switchable_gfx_is_enabled_func)(void); > + bool enabled; > + > + /* Only need to check for Dell laptops and AIOs */ > + if (!dmi_find_device(DMI_DEV_TYPE_OEM_STRING, "Dell System", NULL) || > + !(dmi_match(DMI_CHASSIS_TYPE, "10") || > + dmi_match(DMI_CHASSIS_TYPE, "13")) || > + !(pdev->vendor == PCI_VENDOR_ID_ATI || > + pdev->vendor == PCI_VENDOR_ID_NVIDIA)) > + return false; > + > + dell_switchable_gfx_is_enabled_func = > + symbol_request(dell_switchable_gfx_is_enabled); > + if (!dell_switchable_gfx_is_enabled_func) > + return false; > + > + enabled = dell_switchable_gfx_is_enabled_func(); > + > + symbol_put(dell_switchable_gfx_is_enabled); > + > + return enabled; > +} > +#else > +static bool check_dell_switchable_gfx(struct pci_dev *pdev) > +{ > + return false; > +} > +#endif > + > /* check the snoop mode availability */ > static void azx_check_snoop_available(struct azx *chip) > { > @@ -1711,6 +1745,11 @@ static int azx_create(struct snd_card *card, struct pci_dev *pci, > if (err < 0) > return err; > > + if (check_dell_switchable_gfx(pci)) { > + pci_disable_device(pci); > + return -ENODEV; > + } > + > hda = kzalloc(sizeof(*hda), GFP_KERNEL); > if (!hda) { > pci_disable_device(pci); > -- > 2.17.0 > >