For Intel Haswell chip, HDA controller and codec have power well dependency from GPU side. This patch added support to request/release power well in audio driver. Power save feature should be enabled to get runtime power saving.
There's deadlock when request_module(i915) in azx_probe. It looks like: device_lock(audio pci device) -> azx_probe -> module_request (or symbol_request) -> modprobe (userspace) -> i915 init -> drm_pci_init -> pci_register_driver -> bus_add_driver -> driver_attach -> which in turn tries all locks on pci bus, and when it tries the one on the audio device, it will deadlock.
This patch introduce a work to store remaining probe stuff, and let request_module run in safe work context.
Signed-off-by: Wang Xingchao xingchao.wang@linux.intel.com --- sound/pci/hda/Kconfig | 10 ++++++ sound/pci/hda/Makefile | 2 ++ sound/pci/hda/hda_i915.c | 75 +++++++++++++++++++++++++++++++++++++++++++++ sound/pci/hda/hda_i915.h | 35 +++++++++++++++++++++ sound/pci/hda/hda_intel.c | 60 ++++++++++++++++++++++++++++++++++-- 5 files changed, 179 insertions(+), 3 deletions(-) create mode 100644 sound/pci/hda/hda_i915.c create mode 100644 sound/pci/hda/hda_i915.h
diff --git a/sound/pci/hda/Kconfig b/sound/pci/hda/Kconfig index 80a7d44..c5a872c 100644 --- a/sound/pci/hda/Kconfig +++ b/sound/pci/hda/Kconfig @@ -152,6 +152,16 @@ config SND_HDA_CODEC_HDMI snd-hda-codec-hdmi. This module is automatically loaded at probing.
+config SND_HDA_I915 + bool "Build Display HD-audio controller/codec power well support for i915 cards" + depends on DRM_I915 + help + Say Y here to include full HDMI and DisplayPort HD-audio controller/codec + power-well support for Intel Haswell graphics cards based on the i915 driver. + + Note that this option must be enabled for Intel Haswell C+ stepping machines, otherwise + the GPU audio controller/codecs will not be initialized or damaged when exit from S3 mode. + config SND_HDA_CODEC_CIRRUS bool "Build Cirrus Logic codec support" default y diff --git a/sound/pci/hda/Makefile b/sound/pci/hda/Makefile index 24a2514..c091438 100644 --- a/sound/pci/hda/Makefile +++ b/sound/pci/hda/Makefile @@ -1,4 +1,6 @@ snd-hda-intel-objs := hda_intel.o +# for haswell power well +snd-hda-intel-$(CONFIG_SND_HDA_I915) += hda_i915.o
snd-hda-codec-y := hda_codec.o hda_jack.o hda_auto_parser.o snd-hda-codec-$(CONFIG_SND_HDA_GENERIC) += hda_generic.o diff --git a/sound/pci/hda/hda_i915.c b/sound/pci/hda/hda_i915.c new file mode 100644 index 0000000..76c13d5 --- /dev/null +++ b/sound/pci/hda/hda_i915.c @@ -0,0 +1,75 @@ +/* + * hda_i915.c - routines for Haswell HDA controller power well support + * + * This program is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License as published by the Free + * Software Foundation; either version 2 of the License, or (at your option) + * any later version. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY + * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License + * for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software Foundation, + * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. + */ + +#include <linux/init.h> +#include <linux/module.h> +#include <sound/core.h> +#include <drm/i915_powerwell.h> +#include "hda_i915.h" + +static void (*get_power)(void); +static void (*put_power)(void); + +void hda_display_power(bool enable) +{ + if (!get_power || !put_power) + return; + + snd_printdd("HDA display power %s \n", + enable ? "Enable" : "Disable"); + if (enable) + get_power(); + else + put_power(); +} + +int hda_i915_init(void) +{ + int err = 0; + + get_power = symbol_request(i915_request_power_well); + if (!get_power) { + snd_printk(KERN_WARNING "hda-i915: get_power symbol get fail\n"); + return -ENODEV; + } + + put_power = symbol_request(i915_release_power_well); + if (!put_power) { + symbol_put(i915_request_power_well); + get_power = NULL; + return -ENODEV; + } + + snd_printd("HDA driver get symbol successfully from i915 module\n"); + + return err; +} + +int hda_i915_exit(void) +{ + if (get_power) { + symbol_put(i915_request_power_well); + get_power = NULL; + } + if (put_power) { + symbol_put(i915_release_power_well); + put_power = NULL; + } + + return 0; +} diff --git a/sound/pci/hda/hda_i915.h b/sound/pci/hda/hda_i915.h new file mode 100644 index 0000000..5a63da2 --- /dev/null +++ b/sound/pci/hda/hda_i915.h @@ -0,0 +1,35 @@ +/* + * This program is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License as published by the Free + * Software Foundation; either version 2 of the License, or (at your option) + * any later version. + * + * This program is distributed in the hope that it will be useful, but WITHOUT + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for + * more details. + * + * You should have received a copy of the GNU General Public License along with + * this program; if not, write to the Free Software Foundation, Inc., 59 + * Temple Place - Suite 330, Boston, MA 02111-1307, USA. + */ +#ifndef __SOUND_HDA_I915_H +#define __SOUND_HDA_I915_H + +#ifdef CONFIG_SND_HDA_I915 +void hda_display_power(bool enable); +int hda_i915_init(void); +int hda_i915_exit(void); +#else +static inline void hda_display_power(bool enable) {} +static inline int hda_i915_init(void) +{ + return -ENODEV; +} +static inline int hda_i915_exit(void) +{ + return 0; +} +#endif + +#endif diff --git a/sound/pci/hda/hda_intel.c b/sound/pci/hda/hda_intel.c index 49cc942..1dedcb1 100644 --- a/sound/pci/hda/hda_intel.c +++ b/sound/pci/hda/hda_intel.c @@ -62,6 +62,7 @@ #include <linux/vga_switcheroo.h> #include <linux/firmware.h> #include "hda_codec.h" +#include "hda_i915.h"
static int index[SNDRV_CARDS] = SNDRV_DEFAULT_IDX; @@ -541,6 +542,10 @@ struct azx { /* for pending irqs */ struct work_struct irq_pending_work;
+#ifdef CONFIG_SND_HDA_I915 + struct work_struct probe_work; +#endif + /* reboot notifier (for mysterious hangup problem at power-down) */ struct notifier_block reboot_notifier;
@@ -594,6 +599,7 @@ enum { #define AZX_DCAPS_4K_BDLE_BOUNDARY (1 << 23) /* BDLE in 4k boundary */ #define AZX_DCAPS_COUNT_LPIB_DELAY (1 << 25) /* Take LPIB as delay */ #define AZX_DCAPS_PM_RUNTIME (1 << 26) /* runtime PM support */ +#define AZX_DCAPS_I915_POWERWELL (1 << 27) /* HSW i915 power well support */
/* quirks for Intel PCH */ #define AZX_DCAPS_INTEL_PCH_NOPM \ @@ -2869,6 +2875,8 @@ static int azx_suspend(struct device *dev) pci_disable_device(pci); pci_save_state(pci); pci_set_power_state(pci, PCI_D3hot); + if (chip->driver_caps & AZX_DCAPS_I915_POWERWELL) + hda_display_power(false); return 0; }
@@ -2881,6 +2889,8 @@ static int azx_resume(struct device *dev) if (chip->disabled) return 0;
+ if (chip->driver_caps & AZX_DCAPS_I915_POWERWELL) + hda_display_power(true); pci_set_power_state(pci, PCI_D0); pci_restore_state(pci); if (pci_enable_device(pci) < 0) { @@ -2913,6 +2923,8 @@ static int azx_runtime_suspend(struct device *dev)
azx_stop_chip(chip); azx_clear_irq_pending(chip); + if (chip->driver_caps & AZX_DCAPS_I915_POWERWELL) + hda_display_power(false); return 0; }
@@ -2921,6 +2933,8 @@ static int azx_runtime_resume(struct device *dev) struct snd_card *card = dev_get_drvdata(dev); struct azx *chip = card->private_data;
+ if (chip->driver_caps & AZX_DCAPS_I915_POWERWELL) + hda_display_power(true); azx_init_pci(chip); azx_init_chip(chip, 1); return 0; @@ -3147,6 +3161,10 @@ static int azx_free(struct azx *chip) if (chip->fw) release_firmware(chip->fw); #endif + if (chip->driver_caps & AZX_DCAPS_I915_POWERWELL) { + hda_display_power(false); + hda_i915_exit(); + } kfree(chip);
return 0; @@ -3372,6 +3390,13 @@ static void azx_check_snoop_available(struct azx *chip) } }
+#ifdef CONFIG_SND_HDA_I915 +static void azx_probe_work(struct work_struct *work) +{ + azx_probe_continue(container_of(work, struct azx, probe_work)); +} +#endif + /* * constructor */ @@ -3447,7 +3472,13 @@ static int azx_create(struct snd_card *card, struct pci_dev *pci, return err; }
+#ifdef CONFIG_SND_HDA_I915 + /* continue probing in work context as may trigger request module */ + INIT_WORK(&chip->probe_work, azx_probe_work); +#endif + *rchip = chip; + return 0; }
@@ -3718,6 +3749,16 @@ static int azx_probe(struct pci_dev *pci, } #endif /* CONFIG_SND_HDA_PATCH_LOADER */
+ /* continue probing in work context, avoid request_module deadlock */ + if (probe_now && (chip->driver_caps & AZX_DCAPS_I915_POWERWELL)) { +#ifdef CONFIG_SND_HDA_I915 + probe_now = false; + schedule_work(&chip->probe_work); +#else + snd_printk(KERN_ERR SFX "Haswell must build in CONFIG_SND_HDA_I915\n"); +#endif + } + if (probe_now) { err = azx_probe_continue(chip); if (err < 0) @@ -3740,6 +3781,16 @@ static int azx_probe_continue(struct azx *chip) int dev = chip->dev_index; int err;
+ /* Request power well for Haswell HDA controller and codec */ + if (chip->driver_caps & AZX_DCAPS_I915_POWERWELL) { + err = hda_i915_init(); + if (err < 0) { + snd_printk(KERN_ERR SFX "Error request power-well from i915\n"); + goto out_free; + } + hda_display_power(true); + } + err = azx_first_init(chip); if (err < 0) goto out_free; @@ -3834,11 +3885,14 @@ static DEFINE_PCI_DEVICE_TABLE(azx_ids) = { .driver_data = AZX_DRIVER_PCH | AZX_DCAPS_INTEL_PCH }, /* Haswell */ { PCI_DEVICE(0x8086, 0x0a0c), - .driver_data = AZX_DRIVER_SCH | AZX_DCAPS_INTEL_PCH }, + .driver_data = AZX_DRIVER_SCH | AZX_DCAPS_INTEL_PCH | + AZX_DCAPS_I915_POWERWELL }, { PCI_DEVICE(0x8086, 0x0c0c), - .driver_data = AZX_DRIVER_SCH | AZX_DCAPS_INTEL_PCH }, + .driver_data = AZX_DRIVER_SCH | AZX_DCAPS_INTEL_PCH | + AZX_DCAPS_I915_POWERWELL }, { PCI_DEVICE(0x8086, 0x0d0c), - .driver_data = AZX_DRIVER_SCH | AZX_DCAPS_INTEL_PCH }, + .driver_data = AZX_DRIVER_SCH | AZX_DCAPS_INTEL_PCH | + AZX_DCAPS_I915_POWERWELL }, /* 5 Series/3400 */ { PCI_DEVICE(0x8086, 0x3b56), .driver_data = AZX_DRIVER_SCH | AZX_DCAPS_INTEL_PCH_NOPM },