[PATCH 0/2 V4] Power-well API implementation for Haswell

[PATCH 0/2 V4] Power-well API implementation for Haswell

[Wang Xingchao]

Hi all,

   This is V4 and here're some changes notes:

   change between V3-->V4:
   - add new structure i915_power_well
   - initialize drm_device pointer at module init time
   - change function name

   change between V2-->V3:
   - make SND_HDA_I915 selectable
   - use snd_printdd to output message
   - add return error code check
   - use symbol_request to replace symbol_get
   - release power_well at azx_free
   - some typo fixes

   changes between V1-->V2:
   - use reference count to track power-well usage
   - remove external module, compiled into snd-hda-intel instead
   - manage symbols and module loading properly
   - remove IS_HSW macro, use flag instead
   - remove audio callback for gfx driver to avoid dependency 
   - split whole patch into two pieces for easy review
   - more typo fixes

Wang Xingchao (2):
  i915/drm: Add private api for power well usage
  ALSA: hda - Add power-welll support for haswell HDA

 drivers/gpu/drm/i915/i915_dma.c  |    6 +++
 drivers/gpu/drm/i915/i915_drv.h  |   12 +++++
 drivers/gpu/drm/i915/intel_drv.h |    4 ++
 drivers/gpu/drm/i915/intel_pm.c  |   98 +++++++++++++++++++++++++++++++++++---
 include/drm/i915_powerwell.h     |   36 ++++++++++++++
 sound/pci/hda/Kconfig            |   10 ++++
 sound/pci/hda/Makefile           |    3 ++
 sound/pci/hda/hda_i915.c         |   75 +++++++++++++++++++++++++++++
 sound/pci/hda/hda_i915.h         |   35 ++++++++++++++
 sound/pci/hda/hda_intel.c        |   41 ++++++++++++++--
 10 files changed, 310 insertions(+), 10 deletions(-)
 create mode 100644 include/drm/i915_powerwell.h
 create mode 100644 sound/pci/hda/hda_i915.c
 create mode 100644 sound/pci/hda/hda_i915.h

-- 
1.7.9.5

[PATCH 1/2 V4] i915/drm: Add private api for power well usage

[Wang Xingchao]

Haswell Display audio depends on power well in graphic side, it should
request power well before use it and release power well after use.
I915 will not shutdown power well if it detects audio is using.
This patch protects display audio crash for Intel Haswell C3 stepping board.

Signed-off-by: Wang Xingchao <xingchao.wang@linux.intel.com>
---
 drivers/gpu/drm/i915/i915_dma.c  |    6 +++
 drivers/gpu/drm/i915/i915_drv.h  |   12 +++++
 drivers/gpu/drm/i915/intel_drv.h |    4 ++
 drivers/gpu/drm/i915/intel_pm.c  |   98 +++++++++++++++++++++++++++++++++++---
 include/drm/i915_powerwell.h     |   36 ++++++++++++++
 5 files changed, 149 insertions(+), 7 deletions(-)
 create mode 100644 include/drm/i915_powerwell.h

diff --git a/drivers/gpu/drm/i915/i915_dma.c b/drivers/gpu/drm/i915/i915_dma.c
index a1648eb..2b9010a 100644
--- a/drivers/gpu/drm/i915/i915_dma.c
+++ b/drivers/gpu/drm/i915/i915_dma.c
@@ -1652,6 +1652,9 @@ int i915_driver_load(struct drm_device *dev, unsigned long flags)
 	/* Start out suspended */
 	dev_priv->mm.suspended = 1;
 
+	if (IS_HASWELL(dev))
+		i915_init_power_well(dev);
+
 	if (drm_core_check_feature(dev, DRIVER_MODESET)) {
 		ret = i915_load_modeset_init(dev);
 		if (ret < 0) {
@@ -1708,6 +1711,9 @@ int i915_driver_unload(struct drm_device *dev)
 
 	intel_gpu_ips_teardown();
 
+	if (IS_HASWELL(dev))
+		i915_remove_power_well(dev);
+
 	i915_teardown_sysfs(dev);
 
 	if (dev_priv->mm.inactive_shrinker.shrink)
diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 3ac71db..a0f1a6d 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -702,6 +702,15 @@ struct intel_ilk_power_mgmt {
 	struct drm_i915_gem_object *renderctx;
 };
 
+/* Power well structure for haswell */
+struct i915_power_well {
+	struct drm_device *device;
+	spinlock_t lock;
+	/* power well enable/disable usage count */
+	int count;
+	int i915_request;
+};
+
 struct i915_dri1_state {
 	unsigned allow_batchbuffer : 1;
 	u32 __iomem *gfx_hws_cpu_addr;
@@ -1048,6 +1057,9 @@ typedef struct drm_i915_private {
 	 * mchdev_lock in intel_pm.c */
 	struct intel_ilk_power_mgmt ips;
 
+	/* Haswell power well */
+	struct i915_power_well *hsw_pwr;
+
 	enum no_fbc_reason no_fbc_reason;
 
 	struct drm_mm_node *compressed_fb;
diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
index dfcf546..efcccab 100644
--- a/drivers/gpu/drm/i915/intel_drv.h
+++ b/drivers/gpu/drm/i915/intel_drv.h
@@ -759,6 +759,10 @@ extern void intel_update_fbc(struct drm_device *dev);
 extern void intel_gpu_ips_init(struct drm_i915_private *dev_priv);
 extern void intel_gpu_ips_teardown(void);
 
+/* Power well */
+extern int i915_init_power_well(struct drm_device *dev);
+extern void i915_remove_power_well(struct drm_device *dev);
+
 extern bool intel_using_power_well(struct drm_device *dev);
 extern void intel_init_power_well(struct drm_device *dev);
 extern void intel_set_power_well(struct drm_device *dev, bool enable);
diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
index 0f4b46e..eec7aa8 100644
--- a/drivers/gpu/drm/i915/intel_pm.c
+++ b/drivers/gpu/drm/i915/intel_pm.c
@@ -4344,18 +4344,12 @@ bool intel_using_power_well(struct drm_device *dev)
 		return true;
 }
 
-void intel_set_power_well(struct drm_device *dev, bool enable)
+static void __intel_set_power_well(struct drm_device *dev, bool enable)
 {
 	struct drm_i915_private *dev_priv = dev->dev_private;
 	bool is_enabled, enable_requested;
 	uint32_t tmp;
 
-	if (!HAS_POWER_WELL(dev))
-		return;
-
-	if (!i915_disable_power_well && !enable)
-		return;
-
 	tmp = I915_READ(HSW_PWR_WELL_DRIVER);
 	is_enabled = tmp & HSW_PWR_WELL_STATE;
 	enable_requested = tmp & HSW_PWR_WELL_ENABLE;
@@ -4378,6 +4372,96 @@ void intel_set_power_well(struct drm_device *dev, bool enable)
 	}
 }
 
+static struct i915_power_well *hsw_pwr;
+
+/* Display audio driver power well request */
+void i915_request_power_well(void)
+{
+	if (hsw_pwr == NULL)
+		return;
+
+	spin_lock_irq(&hsw_pwr->lock);
+	if (!hsw_pwr->count++ &&
+			!hsw_pwr->i915_request)
+		__intel_set_power_well(hsw_pwr->device, true);
+	spin_unlock_irq(&hsw_pwr->lock);
+}
+EXPORT_SYMBOL_GPL(i915_request_power_well);
+
+/* Display audio driver power well release */
+void i915_release_power_well(void)
+{
+	if (hsw_pwr == NULL)
+		return;
+
+	spin_lock_irq(&hsw_pwr->lock);
+
+	/* i915 using power well */
+	if (hsw_pwr->i915_request) {
+		spin_unlock_irq(&hsw_pwr->lock);
+		return;
+	}
+
+	WARN_ON(!hsw_pwr->count);
+	if (!--hsw_pwr->count)
+		__intel_set_power_well(hsw_pwr->device, false);
+	spin_unlock_irq(&hsw_pwr->lock);
+}
+EXPORT_SYMBOL_GPL(i915_release_power_well);
+
+int i915_init_power_well(struct drm_device *dev)
+{
+	struct drm_i915_private *dev_priv = dev->dev_private;
+
+	hsw_pwr = kzalloc(sizeof *hsw_pwr, GFP_KERNEL);
+	if (hsw_pwr == NULL)
+		return -ENOMEM;
+
+	dev_priv->hsw_pwr = hsw_pwr;
+
+	hsw_pwr->device = dev;
+	spin_lock_init(&hsw_pwr->lock);
+	hsw_pwr->count = 0;
+
+	return 0;
+}
+
+void i915_remove_power_well(struct drm_device *dev)
+{
+	struct drm_i915_private *dev_priv = dev->dev_private;
+
+	kfree(dev_priv->hsw_pwr);
+	dev_priv->hsw_pwr = NULL;
+	hsw_pwr = NULL;
+}
+
+void intel_set_power_well(struct drm_device *dev, bool enable)
+{
+	struct drm_i915_private *dev_priv = dev->dev_private;
+	struct i915_power_well *power_well = dev_priv->hsw_pwr;
+
+	if (!HAS_POWER_WELL(dev))
+		return;
+
+	if (!i915_disable_power_well && !enable)
+		return;
+
+	if (!power_well)
+		return;
+
+	spin_lock_irq(&power_well->lock);
+	power_well->i915_request = enable;
+
+	/* only reject "disable" power well request */
+	if (power_well->count && !enable) {
+		spin_unlock_irq(&power_well->lock);
+		return;
+	}
+
+	__intel_set_power_well(dev, enable);
+	spin_unlock_irq(&power_well->lock);
+}
+
 /*
  * Starting with Haswell, we have a "Power Down Well" that can be turned off
  * when not needed anymore. We have 4 registers that can request the power well
diff --git a/include/drm/i915_powerwell.h b/include/drm/i915_powerwell.h
new file mode 100644
index 0000000..cfdc884
--- /dev/null
+++ b/include/drm/i915_powerwell.h
@@ -0,0 +1,36 @@
+/**************************************************************************
+ *
+ * Copyright 2013 Intel Inc.
+ * All Rights Reserved.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sub license, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the
+ * next paragraph) shall be included in all copies or substantial portions
+ * of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
+ * THE COPYRIGHT HOLDERS, AUTHORS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM,
+ * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
+ * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
+ * USE OR OTHER DEALINGS IN THE SOFTWARE.
+ *
+ *
+ **************************************************************************/
+
+#ifndef _I915_POWERWELL_H_
+#define _I915_POWERWELL_H_
+
+/* For use by hda_i915 driver */
+extern void i915_request_power_well(void);
+extern void i915_release_power_well(void);
+
+#endif				/* _I915_POWERWELL_H_ */
-- 
1.7.9.5

[PATCH 2/2 V4] ALSA: hda - Add power-welll support for haswell HDA

[Wang Xingchao]

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.

Signed-off-by: Wang Xingchao <xingchao.wang@linux.intel.com>
---
 sound/pci/hda/Kconfig     |   10 ++++++
 sound/pci/hda/Makefile    |    3 ++
 sound/pci/hda/hda_i915.c  |   75 +++++++++++++++++++++++++++++++++++++++++++++
 sound/pci/hda/hda_i915.h  |   35 +++++++++++++++++++++
 sound/pci/hda/hda_intel.c |   41 +++++++++++++++++++++++--
 5 files changed, 161 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..4b0a4bc 100644
--- a/sound/pci/hda/Makefile
+++ b/sound/pci/hda/Makefile
@@ -6,6 +6,9 @@ snd-hda-codec-$(CONFIG_PROC_FS) += hda_proc.o
 snd-hda-codec-$(CONFIG_SND_HDA_HWDEP) += hda_hwdep.o
 snd-hda-codec-$(CONFIG_SND_HDA_INPUT_BEEP) += hda_beep.o
 
+# for haswell power well
+snd-hda-intel-$(CONFIG_SND_HDA_I915) +=	hda_i915.o
+
 # for trace-points
 CFLAGS_hda_codec.o := -I$(src)
 CFLAGS_hda_intel.o := -I$(src)
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 418bfc0..bf27693 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;
@@ -594,6 +595,7 @@ 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 +2871,8 @@ 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 +2885,8 @@ 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 +2919,8 @@ 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 +2929,8 @@ 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;
@@ -3144,6 +3154,10 @@ 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;
@@ -3700,6 +3714,19 @@ static int azx_probe(struct pci_dev *pci,
 		chip->disabled = true;
 	}
 
+	if (chip->driver_caps & AZX_DCAPS_I915_POWERWELL) {
+#ifdef CONFIG_SND_HDA_I915
+		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);
+#else
+		snd_printk(KERN_ERR SFX "Haswell must build in CONFIG_SND_HDA_I915\n");
+#endif
+	}
+
 	probe_now = !chip->disabled;
 	if (probe_now) {
 		err = azx_first_init(chip);
@@ -3799,6 +3826,7 @@ out_free:
 static void azx_remove(struct pci_dev *pci)
 {
 	struct snd_card *card = pci_get_drvdata(pci);
+	struct azx *chip = card->private_data;
 
 	if (pci_dev_run_wake(pci))
 		pm_runtime_get_noresume(&pci->dev);
@@ -3806,6 +3834,10 @@ static void azx_remove(struct pci_dev *pci)
 	if (card)
 		snd_card_free(card);
 	pci_set_drvdata(pci, NULL);
+	if (chip->driver_caps & AZX_DCAPS_I915_POWERWELL) {
+		hda_display_power(false);
+		hda_i915_exit();
+	}
 }
 
 /* PCI IDs */
@@ -3835,11 +3867,14 @@ 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 },
-- 
1.7.9.5

Re: [PATCH 1/2 V4] i915/drm: Add private api for power well usage

[Takashi Iwai]

At Mon, 20 May 2013 19:26:57 +0800,
Wang Xingchao wrote:
> 
> Haswell Display audio depends on power well in graphic side, it should
> request power well before use it and release power well after use.
> I915 will not shutdown power well if it detects audio is using.
> This patch protects display audio crash for Intel Haswell C3 stepping board.
> 
> Signed-off-by: Wang Xingchao <xingchao.wang@linux.intel.com>
> ---
>  drivers/gpu/drm/i915/i915_dma.c  |    6 +++
>  drivers/gpu/drm/i915/i915_drv.h  |   12 +++++
>  drivers/gpu/drm/i915/intel_drv.h |    4 ++
>  drivers/gpu/drm/i915/intel_pm.c  |   98 +++++++++++++++++++++++++++++++++++---
>  include/drm/i915_powerwell.h     |   36 ++++++++++++++
>  5 files changed, 149 insertions(+), 7 deletions(-)
>  create mode 100644 include/drm/i915_powerwell.h
> 
> diff --git a/drivers/gpu/drm/i915/i915_dma.c b/drivers/gpu/drm/i915/i915_dma.c
> index a1648eb..2b9010a 100644
> --- a/drivers/gpu/drm/i915/i915_dma.c
> +++ b/drivers/gpu/drm/i915/i915_dma.c
> @@ -1652,6 +1652,9 @@ int i915_driver_load(struct drm_device *dev, unsigned long flags)
>  	/* Start out suspended */
>  	dev_priv->mm.suspended = 1;
>  
> +	if (IS_HASWELL(dev))
> +		i915_init_power_well(dev);
> +
>  	if (drm_core_check_feature(dev, DRIVER_MODESET)) {
>  		ret = i915_load_modeset_init(dev);
>  		if (ret < 0) {
> @@ -1708,6 +1711,9 @@ int i915_driver_unload(struct drm_device *dev)
>  
>  	intel_gpu_ips_teardown();
>  
> +	if (IS_HASWELL(dev))
> +		i915_remove_power_well(dev);
> +
>  	i915_teardown_sysfs(dev);
>  
>  	if (dev_priv->mm.inactive_shrinker.shrink)
> diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
> index 3ac71db..a0f1a6d 100644
> --- a/drivers/gpu/drm/i915/i915_drv.h
> +++ b/drivers/gpu/drm/i915/i915_drv.h
> @@ -702,6 +702,15 @@ struct intel_ilk_power_mgmt {
>  	struct drm_i915_gem_object *renderctx;
>  };
>  
> +/* Power well structure for haswell */
> +struct i915_power_well {
> +	struct drm_device *device;
> +	spinlock_t lock;
> +	/* power well enable/disable usage count */
> +	int count;
> +	int i915_request;
> +};
> +
>  struct i915_dri1_state {
>  	unsigned allow_batchbuffer : 1;
>  	u32 __iomem *gfx_hws_cpu_addr;
> @@ -1048,6 +1057,9 @@ typedef struct drm_i915_private {
>  	 * mchdev_lock in intel_pm.c */
>  	struct intel_ilk_power_mgmt ips;
>  
> +	/* Haswell power well */
> +	struct i915_power_well *hsw_pwr;
> +
>  	enum no_fbc_reason no_fbc_reason;
>  
>  	struct drm_mm_node *compressed_fb;
> diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
> index dfcf546..efcccab 100644
> --- a/drivers/gpu/drm/i915/intel_drv.h
> +++ b/drivers/gpu/drm/i915/intel_drv.h
> @@ -759,6 +759,10 @@ extern void intel_update_fbc(struct drm_device *dev);
>  extern void intel_gpu_ips_init(struct drm_i915_private *dev_priv);
>  extern void intel_gpu_ips_teardown(void);
>  
> +/* Power well */
> +extern int i915_init_power_well(struct drm_device *dev);
> +extern void i915_remove_power_well(struct drm_device *dev);
> +
>  extern bool intel_using_power_well(struct drm_device *dev);
>  extern void intel_init_power_well(struct drm_device *dev);
>  extern void intel_set_power_well(struct drm_device *dev, bool enable);
> diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
> index 0f4b46e..eec7aa8 100644
> --- a/drivers/gpu/drm/i915/intel_pm.c
> +++ b/drivers/gpu/drm/i915/intel_pm.c
> @@ -4344,18 +4344,12 @@ bool intel_using_power_well(struct drm_device *dev)
>  		return true;
>  }
>  
> -void intel_set_power_well(struct drm_device *dev, bool enable)
> +static void __intel_set_power_well(struct drm_device *dev, bool enable)
>  {
>  	struct drm_i915_private *dev_priv = dev->dev_private;
>  	bool is_enabled, enable_requested;
>  	uint32_t tmp;
>  
> -	if (!HAS_POWER_WELL(dev))
> -		return;
> -
> -	if (!i915_disable_power_well && !enable)
> -		return;
> -
>  	tmp = I915_READ(HSW_PWR_WELL_DRIVER);
>  	is_enabled = tmp & HSW_PWR_WELL_STATE;
>  	enable_requested = tmp & HSW_PWR_WELL_ENABLE;
> @@ -4378,6 +4372,96 @@ void intel_set_power_well(struct drm_device *dev, bool enable)
>  	}
>  }
>  
> +static struct i915_power_well *hsw_pwr;
> +
> +/* Display audio driver power well request */
> +void i915_request_power_well(void)
> +{
> +	if (hsw_pwr == NULL)
> +		return;
> +
> +	spin_lock_irq(&hsw_pwr->lock);
> +	if (!hsw_pwr->count++ &&
> +			!hsw_pwr->i915_request)
> +		__intel_set_power_well(hsw_pwr->device, true);
> +	spin_unlock_irq(&hsw_pwr->lock);
> +}
> +EXPORT_SYMBOL_GPL(i915_request_power_well);
> +
> +/* Display audio driver power well release */
> +void i915_release_power_well(void)
> +{
> +	if (hsw_pwr == NULL)
> +		return;
> +
> +	spin_lock_irq(&hsw_pwr->lock);
> +
> +	/* i915 using power well */
> +	if (hsw_pwr->i915_request) {
> +		spin_unlock_irq(&hsw_pwr->lock);
> +		return;
> +	}
> +
> +	WARN_ON(!hsw_pwr->count);
> +	if (!--hsw_pwr->count)
> +		__intel_set_power_well(hsw_pwr->device, false);
> +	spin_unlock_irq(&hsw_pwr->lock);
> +}
> +EXPORT_SYMBOL_GPL(i915_release_power_well);

This will result in unbalanced refcount.
When i915_request is true, the count will be never decreased.


Takashi

> +
> +int i915_init_power_well(struct drm_device *dev)
> +{
> +	struct drm_i915_private *dev_priv = dev->dev_private;
> +
> +	hsw_pwr = kzalloc(sizeof *hsw_pwr, GFP_KERNEL);
> +	if (hsw_pwr == NULL)
> +		return -ENOMEM;
> +
> +	dev_priv->hsw_pwr = hsw_pwr;
> +
> +	hsw_pwr->device = dev;
> +	spin_lock_init(&hsw_pwr->lock);
> +	hsw_pwr->count = 0;
> +
> +	return 0;
> +}
> +
> +void i915_remove_power_well(struct drm_device *dev)
> +{
> +	struct drm_i915_private *dev_priv = dev->dev_private;
> +
> +	kfree(dev_priv->hsw_pwr);
> +	dev_priv->hsw_pwr = NULL;
> +	hsw_pwr = NULL;
> +}
> +
> +void intel_set_power_well(struct drm_device *dev, bool enable)
> +{
> +	struct drm_i915_private *dev_priv = dev->dev_private;
> +	struct i915_power_well *power_well = dev_priv->hsw_pwr;
> +
> +	if (!HAS_POWER_WELL(dev))
> +		return;
> +
> +	if (!i915_disable_power_well && !enable)
> +		return;
> +
> +	if (!power_well)
> +		return;
> +
> +	spin_lock_irq(&power_well->lock);
> +	power_well->i915_request = enable;
> +
> +	/* only reject "disable" power well request */
> +	if (power_well->count && !enable) {
> +		spin_unlock_irq(&power_well->lock);
> +		return;
> +	}
> +
> +	__intel_set_power_well(dev, enable);
> +	spin_unlock_irq(&power_well->lock);
> +}
> +
>  /*
>   * Starting with Haswell, we have a "Power Down Well" that can be turned off
>   * when not needed anymore. We have 4 registers that can request the power well
> diff --git a/include/drm/i915_powerwell.h b/include/drm/i915_powerwell.h
> new file mode 100644
> index 0000000..cfdc884
> --- /dev/null
> +++ b/include/drm/i915_powerwell.h
> @@ -0,0 +1,36 @@
> +/**************************************************************************
> + *
> + * Copyright 2013 Intel Inc.
> + * All Rights Reserved.
> + *
> + * Permission is hereby granted, free of charge, to any person obtaining a
> + * copy of this software and associated documentation files (the
> + * "Software"), to deal in the Software without restriction, including
> + * without limitation the rights to use, copy, modify, merge, publish,
> + * distribute, sub license, and/or sell copies of the Software, and to
> + * permit persons to whom the Software is furnished to do so, subject to
> + * the following conditions:
> + *
> + * The above copyright notice and this permission notice (including the
> + * next paragraph) shall be included in all copies or substantial portions
> + * of the Software.
> + *
> + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
> + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
> + * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
> + * THE COPYRIGHT HOLDERS, AUTHORS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM,
> + * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
> + * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
> + * USE OR OTHER DEALINGS IN THE SOFTWARE.
> + *
> + *
> + **************************************************************************/
> +
> +#ifndef _I915_POWERWELL_H_
> +#define _I915_POWERWELL_H_
> +
> +/* For use by hda_i915 driver */
> +extern void i915_request_power_well(void);
> +extern void i915_release_power_well(void);
> +
> +#endif				/* _I915_POWERWELL_H_ */
> -- 
> 1.7.9.5
> 

Re: [PATCH 2/2 V4] ALSA: hda - Add power-welll support for haswell HDA

[Takashi Iwai]

At Mon, 20 May 2013 19:26:58 +0800,
Wang Xingchao wrote:
> 
> 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.
> 
> Signed-off-by: Wang Xingchao <xingchao.wang@linux.intel.com>
> ---
>  sound/pci/hda/Kconfig     |   10 ++++++
>  sound/pci/hda/Makefile    |    3 ++
>  sound/pci/hda/hda_i915.c  |   75 +++++++++++++++++++++++++++++++++++++++++++++
>  sound/pci/hda/hda_i915.h  |   35 +++++++++++++++++++++
>  sound/pci/hda/hda_intel.c |   41 +++++++++++++++++++++++--
>  5 files changed, 161 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..4b0a4bc 100644
> --- a/sound/pci/hda/Makefile
> +++ b/sound/pci/hda/Makefile
> @@ -6,6 +6,9 @@ snd-hda-codec-$(CONFIG_PROC_FS) += hda_proc.o
>  snd-hda-codec-$(CONFIG_SND_HDA_HWDEP) += hda_hwdep.o
>  snd-hda-codec-$(CONFIG_SND_HDA_INPUT_BEEP) += hda_beep.o
>  
> +# for haswell power well
> +snd-hda-intel-$(CONFIG_SND_HDA_I915) +=	hda_i915.o
> +
>  # for trace-points
>  CFLAGS_hda_codec.o := -I$(src)
>  CFLAGS_hda_intel.o := -I$(src)
> 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 418bfc0..bf27693 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;
> @@ -594,6 +595,7 @@ 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 +2871,8 @@ 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 +2885,8 @@ 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 +2919,8 @@ 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 +2929,8 @@ 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;
> @@ -3144,6 +3154,10 @@ 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;
> @@ -3700,6 +3714,19 @@ static int azx_probe(struct pci_dev *pci,
>  		chip->disabled = true;
>  	}
>  
> +	if (chip->driver_caps & AZX_DCAPS_I915_POWERWELL) {
> +#ifdef CONFIG_SND_HDA_I915
> +		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);
> +#else
> +		snd_printk(KERN_ERR SFX "Haswell must build in CONFIG_SND_HDA_I915\n");
> +#endif
> +	}
> +
>  	probe_now = !chip->disabled;
>  	if (probe_now) {
>  		err = azx_first_init(chip);
> @@ -3799,6 +3826,7 @@ out_free:
>  static void azx_remove(struct pci_dev *pci)
>  {
>  	struct snd_card *card = pci_get_drvdata(pci);
> +	struct azx *chip = card->private_data;
>  
>  	if (pci_dev_run_wake(pci))
>  		pm_runtime_get_noresume(&pci->dev);
> @@ -3806,6 +3834,10 @@ static void azx_remove(struct pci_dev *pci)
>  	if (card)
>  		snd_card_free(card);
>  	pci_set_drvdata(pci, NULL);
> +	if (chip->driver_caps & AZX_DCAPS_I915_POWERWELL) {
> +		hda_display_power(false);
> +		hda_i915_exit();
> +	}

As mentioned in the previous post, you can't refer to chip instance at
this point.  It's been already freed in snd_card_free().


Takashi


>  }
>  
>  /* PCI IDs */
> @@ -3835,11 +3867,14 @@ 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 },
> -- 
> 1.7.9.5
> 

Re: [PATCH 2/2 V4] ALSA: hda - Add power-welll support for haswell HDA

[Wang, Xingchao]

> -----Original Message-----
> From: Takashi Iwai [mailto:tiwai@suse.de]
> Sent: Tuesday, May 21, 2013 3:19 PM
> To: Wang Xingchao
> Cc: daniel@ffwll.ch; Girdwood, Liam R; david.henningsson@canonical.com; Lin,
> Mengdong; Li, Jocelyn; alsa-devel@alsa-project.org;
> intel-gfx@lists.freedesktop.org; Barnes, Jesse; Zanoni, Paulo R; Wang,
> Xingchao
> Subject: Re: [PATCH 2/2 V4] ALSA: hda - Add power-welll support for haswell
> HDA
> 
> At Mon, 20 May 2013 19:26:58 +0800,
> Wang Xingchao wrote:
> >
> > 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.
> >
> > Signed-off-by: Wang Xingchao <xingchao.wang@linux.intel.com>
> > ---
> >  sound/pci/hda/Kconfig     |   10 ++++++
> >  sound/pci/hda/Makefile    |    3 ++
> >  sound/pci/hda/hda_i915.c  |   75
> +++++++++++++++++++++++++++++++++++++++++++++
> >  sound/pci/hda/hda_i915.h  |   35 +++++++++++++++++++++
> >  sound/pci/hda/hda_intel.c |   41 +++++++++++++++++++++++--
> >  5 files changed, 161 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..4b0a4bc 100644
> > --- a/sound/pci/hda/Makefile
> > +++ b/sound/pci/hda/Makefile
> > @@ -6,6 +6,9 @@ snd-hda-codec-$(CONFIG_PROC_FS) += hda_proc.o
> >  snd-hda-codec-$(CONFIG_SND_HDA_HWDEP) += hda_hwdep.o
> >  snd-hda-codec-$(CONFIG_SND_HDA_INPUT_BEEP) += hda_beep.o
> >
> > +# for haswell power well
> > +snd-hda-intel-$(CONFIG_SND_HDA_I915) +=	hda_i915.o
> > +
> >  # for trace-points
> >  CFLAGS_hda_codec.o := -I$(src)
> >  CFLAGS_hda_intel.o := -I$(src)
> > 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 418bfc0..bf27693 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; @@ -594,6 +595,7
> > @@ 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 +2871,8 @@ 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 +2885,8 @@ 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 +2919,8 @@ 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 +2929,8 @@ 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;
> > @@ -3144,6 +3154,10 @@ 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;
> > @@ -3700,6 +3714,19 @@ static int azx_probe(struct pci_dev *pci,
> >  		chip->disabled = true;
> >  	}
> >
> > +	if (chip->driver_caps & AZX_DCAPS_I915_POWERWELL) { #ifdef
> > +CONFIG_SND_HDA_I915
> > +		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);
> > +#else
> > +		snd_printk(KERN_ERR SFX "Haswell must build in
> > +CONFIG_SND_HDA_I915\n"); #endif
> > +	}
> > +
> >  	probe_now = !chip->disabled;
> >  	if (probe_now) {
> >  		err = azx_first_init(chip);
> > @@ -3799,6 +3826,7 @@ out_free:
> >  static void azx_remove(struct pci_dev *pci)  {
> >  	struct snd_card *card = pci_get_drvdata(pci);
> > +	struct azx *chip = card->private_data;
> >
> >  	if (pci_dev_run_wake(pci))
> >  		pm_runtime_get_noresume(&pci->dev);
> > @@ -3806,6 +3834,10 @@ static void azx_remove(struct pci_dev *pci)
> >  	if (card)
> >  		snd_card_free(card);
> >  	pci_set_drvdata(pci, NULL);
> > +	if (chip->driver_caps & AZX_DCAPS_I915_POWERWELL) {
> > +		hda_display_power(false);
> > +		hda_i915_exit();
> > +	}
> 
> As mentioned in the previous post, you can't refer to chip instance at this point.
> It's been already freed in snd_card_free().

Oh sorry I misunderstand your point, the code should be put before snd_card_free():
diff --git a/sound/pci/hda/hda_intel.c b/sound/pci/hda/hda_intel.c
index eb25888..e6a07f9 100644
--- a/sound/pci/hda/hda_intel.c
+++ b/sound/pci/hda/hda_intel.c
@@ -3837,13 +3837,14 @@ static void azx_remove(struct pci_dev *pci)
        if (pci_dev_run_wake(pci))
                pm_runtime_get_noresume(&pci->dev);

-       if (card)
-               snd_card_free(card);
-       pci_set_drvdata(pci, NULL);
        if (chip->driver_caps & AZX_DCAPS_I915_POWERWELL) {
                hda_display_power(false);
                hda_i915_exit();
        }
+
+       if (card)
+               snd_card_free(card);
+       pci_set_drvdata(pci, NULL);
 }

 /* PCI IDs */

But I'm thinking it can be removed totally as azx_dev_free() always do that.

Thanks
--xingchao

> 
> 
> Takashi
> 
> 
> >  }
> >
> >  /* PCI IDs */
> > @@ -3835,11 +3867,14 @@ 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 },
> > --
> > 1.7.9.5
> >

Re: [PATCH 1/2 V4] i915/drm: Add private api for power well usage

[Wang, Xingchao]

> -----Original Message-----
> From: Takashi Iwai [mailto:tiwai@suse.de]
> Sent: Tuesday, May 21, 2013 3:18 PM
> To: Wang Xingchao
> Cc: daniel@ffwll.ch; Girdwood, Liam R; david.henningsson@canonical.com; Lin,
> Mengdong; Li, Jocelyn; alsa-devel@alsa-project.org;
> intel-gfx@lists.freedesktop.org; Barnes, Jesse; Zanoni, Paulo R; Wang,
> Xingchao
> Subject: Re: [PATCH 1/2 V4] i915/drm: Add private api for power well usage
> 
> At Mon, 20 May 2013 19:26:57 +0800,
> Wang Xingchao wrote:
> >
> > Haswell Display audio depends on power well in graphic side, it should
> > request power well before use it and release power well after use.
> > I915 will not shutdown power well if it detects audio is using.
> > This patch protects display audio crash for Intel Haswell C3 stepping board.
> >
> > Signed-off-by: Wang Xingchao <xingchao.wang@linux.intel.com>
> > ---
> >  drivers/gpu/drm/i915/i915_dma.c  |    6 +++
> >  drivers/gpu/drm/i915/i915_drv.h  |   12 +++++
> >  drivers/gpu/drm/i915/intel_drv.h |    4 ++
> >  drivers/gpu/drm/i915/intel_pm.c  |   98
> +++++++++++++++++++++++++++++++++++---
> >  include/drm/i915_powerwell.h     |   36 ++++++++++++++
> >  5 files changed, 149 insertions(+), 7 deletions(-)  create mode
> > 100644 include/drm/i915_powerwell.h
> >
> > diff --git a/drivers/gpu/drm/i915/i915_dma.c
> > b/drivers/gpu/drm/i915/i915_dma.c index a1648eb..2b9010a 100644
> > --- a/drivers/gpu/drm/i915/i915_dma.c
> > +++ b/drivers/gpu/drm/i915/i915_dma.c
> > @@ -1652,6 +1652,9 @@ int i915_driver_load(struct drm_device *dev,
> unsigned long flags)
> >  	/* Start out suspended */
> >  	dev_priv->mm.suspended = 1;
> >
> > +	if (IS_HASWELL(dev))
> > +		i915_init_power_well(dev);
> > +
> >  	if (drm_core_check_feature(dev, DRIVER_MODESET)) {
> >  		ret = i915_load_modeset_init(dev);
> >  		if (ret < 0) {
> > @@ -1708,6 +1711,9 @@ int i915_driver_unload(struct drm_device *dev)
> >
> >  	intel_gpu_ips_teardown();
> >
> > +	if (IS_HASWELL(dev))
> > +		i915_remove_power_well(dev);
> > +
> >  	i915_teardown_sysfs(dev);
> >
> >  	if (dev_priv->mm.inactive_shrinker.shrink)
> > diff --git a/drivers/gpu/drm/i915/i915_drv.h
> > b/drivers/gpu/drm/i915/i915_drv.h index 3ac71db..a0f1a6d 100644
> > --- a/drivers/gpu/drm/i915/i915_drv.h
> > +++ b/drivers/gpu/drm/i915/i915_drv.h
> > @@ -702,6 +702,15 @@ struct intel_ilk_power_mgmt {
> >  	struct drm_i915_gem_object *renderctx;  };
> >
> > +/* Power well structure for haswell */ struct i915_power_well {
> > +	struct drm_device *device;
> > +	spinlock_t lock;
> > +	/* power well enable/disable usage count */
> > +	int count;
> > +	int i915_request;
> > +};
> > +
> >  struct i915_dri1_state {
> >  	unsigned allow_batchbuffer : 1;
> >  	u32 __iomem *gfx_hws_cpu_addr;
> > @@ -1048,6 +1057,9 @@ typedef struct drm_i915_private {
> >  	 * mchdev_lock in intel_pm.c */
> >  	struct intel_ilk_power_mgmt ips;
> >
> > +	/* Haswell power well */
> > +	struct i915_power_well *hsw_pwr;
> > +
> >  	enum no_fbc_reason no_fbc_reason;
> >
> >  	struct drm_mm_node *compressed_fb;
> > diff --git a/drivers/gpu/drm/i915/intel_drv.h
> > b/drivers/gpu/drm/i915/intel_drv.h
> > index dfcf546..efcccab 100644
> > --- a/drivers/gpu/drm/i915/intel_drv.h
> > +++ b/drivers/gpu/drm/i915/intel_drv.h
> > @@ -759,6 +759,10 @@ extern void intel_update_fbc(struct drm_device
> > *dev);  extern void intel_gpu_ips_init(struct drm_i915_private
> > *dev_priv);  extern void intel_gpu_ips_teardown(void);
> >
> > +/* Power well */
> > +extern int i915_init_power_well(struct drm_device *dev); extern void
> > +i915_remove_power_well(struct drm_device *dev);
> > +
> >  extern bool intel_using_power_well(struct drm_device *dev);  extern
> > void intel_init_power_well(struct drm_device *dev);  extern void
> > intel_set_power_well(struct drm_device *dev, bool enable); diff --git
> > a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
> > index 0f4b46e..eec7aa8 100644
> > --- a/drivers/gpu/drm/i915/intel_pm.c
> > +++ b/drivers/gpu/drm/i915/intel_pm.c
> > @@ -4344,18 +4344,12 @@ bool intel_using_power_well(struct drm_device
> *dev)
> >  		return true;
> >  }
> >
> > -void intel_set_power_well(struct drm_device *dev, bool enable)
> > +static void __intel_set_power_well(struct drm_device *dev, bool
> > +enable)
> >  {
> >  	struct drm_i915_private *dev_priv = dev->dev_private;
> >  	bool is_enabled, enable_requested;
> >  	uint32_t tmp;
> >
> > -	if (!HAS_POWER_WELL(dev))
> > -		return;
> > -
> > -	if (!i915_disable_power_well && !enable)
> > -		return;
> > -
> >  	tmp = I915_READ(HSW_PWR_WELL_DRIVER);
> >  	is_enabled = tmp & HSW_PWR_WELL_STATE;
> >  	enable_requested = tmp & HSW_PWR_WELL_ENABLE; @@ -4378,6
> +4372,96 @@
> > void intel_set_power_well(struct drm_device *dev, bool enable)
> >  	}
> >  }
> >
> > +static struct i915_power_well *hsw_pwr;
> > +
> > +/* Display audio driver power well request */ void
> > +i915_request_power_well(void) {
> > +	if (hsw_pwr == NULL)
> > +		return;
> > +
> > +	spin_lock_irq(&hsw_pwr->lock);
> > +	if (!hsw_pwr->count++ &&
> > +			!hsw_pwr->i915_request)
> > +		__intel_set_power_well(hsw_pwr->device, true);
> > +	spin_unlock_irq(&hsw_pwr->lock);
> > +}
> > +EXPORT_SYMBOL_GPL(i915_request_power_well);
> > +
> > +/* Display audio driver power well release */ void
> > +i915_release_power_well(void) {
> > +	if (hsw_pwr == NULL)
> > +		return;
> > +
> > +	spin_lock_irq(&hsw_pwr->lock);
> > +
> > +	/* i915 using power well */
> > +	if (hsw_pwr->i915_request) {
> > +		spin_unlock_irq(&hsw_pwr->lock);
> > +		return;
> > +	}
> > +
> > +	WARN_ON(!hsw_pwr->count);
> > +	if (!--hsw_pwr->count)
> > +		__intel_set_power_well(hsw_pwr->device, false);
> > +	spin_unlock_irq(&hsw_pwr->lock);
> > +}
> > +EXPORT_SYMBOL_GPL(i915_release_power_well);
> 
> This will result in unbalanced refcount.
> When i915_request is true, the count will be never decreased.
> 

Thanks for pointing out this mistake. Will fix it for next version.

--xingchao


> Takashi
> 
> > +
> > +int i915_init_power_well(struct drm_device *dev) {
> > +	struct drm_i915_private *dev_priv = dev->dev_private;
> > +
> > +	hsw_pwr = kzalloc(sizeof *hsw_pwr, GFP_KERNEL);
> > +	if (hsw_pwr == NULL)
> > +		return -ENOMEM;
> > +
> > +	dev_priv->hsw_pwr = hsw_pwr;
> > +
> > +	hsw_pwr->device = dev;
> > +	spin_lock_init(&hsw_pwr->lock);
> > +	hsw_pwr->count = 0;
> > +
> > +	return 0;
> > +}
> > +
> > +void i915_remove_power_well(struct drm_device *dev) {
> > +	struct drm_i915_private *dev_priv = dev->dev_private;
> > +
> > +	kfree(dev_priv->hsw_pwr);
> > +	dev_priv->hsw_pwr = NULL;
> > +	hsw_pwr = NULL;
> > +}
> > +
> > +void intel_set_power_well(struct drm_device *dev, bool enable) {
> > +	struct drm_i915_private *dev_priv = dev->dev_private;
> > +	struct i915_power_well *power_well = dev_priv->hsw_pwr;
> > +
> > +	if (!HAS_POWER_WELL(dev))
> > +		return;
> > +
> > +	if (!i915_disable_power_well && !enable)
> > +		return;
> > +
> > +	if (!power_well)
> > +		return;
> > +
> > +	spin_lock_irq(&power_well->lock);
> > +	power_well->i915_request = enable;
> > +
> > +	/* only reject "disable" power well request */
> > +	if (power_well->count && !enable) {
> > +		spin_unlock_irq(&power_well->lock);
> > +		return;
> > +	}
> > +
> > +	__intel_set_power_well(dev, enable);
> > +	spin_unlock_irq(&power_well->lock);
> > +}
> > +
> >  /*
> >   * Starting with Haswell, we have a "Power Down Well" that can be turned
> off
> >   * when not needed anymore. We have 4 registers that can request the
> > power well diff --git a/include/drm/i915_powerwell.h
> > b/include/drm/i915_powerwell.h new file mode 100644 index
> > 0000000..cfdc884
> > --- /dev/null
> > +++ b/include/drm/i915_powerwell.h
> > @@ -0,0 +1,36 @@
> >
> +/**************************************************************
> ******
> > +******
> > + *
> > + * Copyright 2013 Intel Inc.
> > + * All Rights Reserved.
> > + *
> > + * Permission is hereby granted, free of charge, to any person
> > +obtaining a
> > + * copy of this software and associated documentation files (the
> > + * "Software"), to deal in the Software without restriction,
> > +including
> > + * without limitation the rights to use, copy, modify, merge,
> > +publish,
> > + * distribute, sub license, and/or sell copies of the Software, and
> > +to
> > + * permit persons to whom the Software is furnished to do so, subject
> > +to
> > + * the following conditions:
> > + *
> > + * The above copyright notice and this permission notice (including
> > +the
> > + * next paragraph) shall be included in all copies or substantial
> > +portions
> > + * of the Software.
> > + *
> > + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY
> KIND,
> > +EXPRESS OR
> > + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
> > +MERCHANTABILITY,
> > + * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO
> EVENT
> > +SHALL
> > + * THE COPYRIGHT HOLDERS, AUTHORS AND/OR ITS SUPPLIERS BE LIABLE
> FOR
> > +ANY CLAIM,
> > + * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
> TORT
> > +OR
> > + * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
> SOFTWARE
> > +OR THE
> > + * USE OR OTHER DEALINGS IN THE SOFTWARE.
> > + *
> > + *
> > +
> >
> +***************************************************************
> ******
> > +*****/
> > +
> > +#ifndef _I915_POWERWELL_H_
> > +#define _I915_POWERWELL_H_
> > +
> > +/* For use by hda_i915 driver */
> > +extern void i915_request_power_well(void); extern void
> > +i915_release_power_well(void);
> > +
> > +#endif				/* _I915_POWERWELL_H_ */
> > --
> > 1.7.9.5
> >

Re: [PATCH 2/2 V4] ALSA: hda - Add power-welll support for haswell HDA

[Takashi Iwai]

At Tue, 21 May 2013 10:58:36 +0000,
Wang, Xingchao wrote:
> 
> 
> > -----Original Message-----
> > From: Takashi Iwai [mailto:tiwai@suse.de]
> > Sent: Tuesday, May 21, 2013 3:19 PM
> > To: Wang Xingchao
> > Cc: daniel@ffwll.ch; Girdwood, Liam R; david.henningsson@canonical.com; Lin,
> > Mengdong; Li, Jocelyn; alsa-devel@alsa-project.org;
> > intel-gfx@lists.freedesktop.org; Barnes, Jesse; Zanoni, Paulo R; Wang,
> > Xingchao
> > Subject: Re: [PATCH 2/2 V4] ALSA: hda - Add power-welll support for haswell
> > HDA
> > 
> > At Mon, 20 May 2013 19:26:58 +0800,
> > Wang Xingchao wrote:
> > >
> > > 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.
> > >
> > > Signed-off-by: Wang Xingchao <xingchao.wang@linux.intel.com>
> > > ---
> > >  sound/pci/hda/Kconfig     |   10 ++++++
> > >  sound/pci/hda/Makefile    |    3 ++
> > >  sound/pci/hda/hda_i915.c  |   75
> > +++++++++++++++++++++++++++++++++++++++++++++
> > >  sound/pci/hda/hda_i915.h  |   35 +++++++++++++++++++++
> > >  sound/pci/hda/hda_intel.c |   41 +++++++++++++++++++++++--
> > >  5 files changed, 161 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..4b0a4bc 100644
> > > --- a/sound/pci/hda/Makefile
> > > +++ b/sound/pci/hda/Makefile
> > > @@ -6,6 +6,9 @@ snd-hda-codec-$(CONFIG_PROC_FS) += hda_proc.o
> > >  snd-hda-codec-$(CONFIG_SND_HDA_HWDEP) += hda_hwdep.o
> > >  snd-hda-codec-$(CONFIG_SND_HDA_INPUT_BEEP) += hda_beep.o
> > >
> > > +# for haswell power well
> > > +snd-hda-intel-$(CONFIG_SND_HDA_I915) +=	hda_i915.o
> > > +
> > >  # for trace-points
> > >  CFLAGS_hda_codec.o := -I$(src)
> > >  CFLAGS_hda_intel.o := -I$(src)
> > > 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 418bfc0..bf27693 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; @@ -594,6 +595,7
> > > @@ 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 +2871,8 @@ 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 +2885,8 @@ 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 +2919,8 @@ 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 +2929,8 @@ 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;
> > > @@ -3144,6 +3154,10 @@ 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;
> > > @@ -3700,6 +3714,19 @@ static int azx_probe(struct pci_dev *pci,
> > >  		chip->disabled = true;
> > >  	}
> > >
> > > +	if (chip->driver_caps & AZX_DCAPS_I915_POWERWELL) { #ifdef
> > > +CONFIG_SND_HDA_I915
> > > +		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);
> > > +#else
> > > +		snd_printk(KERN_ERR SFX "Haswell must build in
> > > +CONFIG_SND_HDA_I915\n"); #endif
> > > +	}
> > > +
> > >  	probe_now = !chip->disabled;
> > >  	if (probe_now) {
> > >  		err = azx_first_init(chip);
> > > @@ -3799,6 +3826,7 @@ out_free:
> > >  static void azx_remove(struct pci_dev *pci)  {
> > >  	struct snd_card *card = pci_get_drvdata(pci);
> > > +	struct azx *chip = card->private_data;
> > >
> > >  	if (pci_dev_run_wake(pci))
> > >  		pm_runtime_get_noresume(&pci->dev);
> > > @@ -3806,6 +3834,10 @@ static void azx_remove(struct pci_dev *pci)
> > >  	if (card)
> > >  		snd_card_free(card);
> > >  	pci_set_drvdata(pci, NULL);
> > > +	if (chip->driver_caps & AZX_DCAPS_I915_POWERWELL) {
> > > +		hda_display_power(false);
> > > +		hda_i915_exit();
> > > +	}
> > 
> > As mentioned in the previous post, you can't refer to chip instance at this point.
> > It's been already freed in snd_card_free().
> 
> Oh sorry I misunderstand your point, the code should be put before snd_card_free():
> diff --git a/sound/pci/hda/hda_intel.c b/sound/pci/hda/hda_intel.c
> index eb25888..e6a07f9 100644
> --- a/sound/pci/hda/hda_intel.c
> +++ b/sound/pci/hda/hda_intel.c
> @@ -3837,13 +3837,14 @@ static void azx_remove(struct pci_dev *pci)
>         if (pci_dev_run_wake(pci))
>                 pm_runtime_get_noresume(&pci->dev);
> 
> -       if (card)
> -               snd_card_free(card);
> -       pci_set_drvdata(pci, NULL);
>         if (chip->driver_caps & AZX_DCAPS_I915_POWERWELL) {
>                 hda_display_power(false);
>                 hda_i915_exit();
>         }
> +
> +       if (card)
> +               snd_card_free(card);
> +       pci_set_drvdata(pci, NULL);
>  }
> 
>  /* PCI IDs */
> 
> But I'm thinking it can be removed totally as azx_dev_free() always do that.

Yeah, the right place to call this is azx_free().
But make sure that this won't be called in the case of error path
before hda_i915_init().


Takashi