[Intel-gfx] [PATCH] drm/i915: Add private api for power well usage

Wang Xingchao xingchao.wang at linux.intel.com
Wed Apr 24 09:15:00 CEST 2013


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 mobile
C3 stepping board.

Signed-off-by: Wang Xingchao <xingchao.wang at linux.intel.com>
---
 drivers/gpu/drm/i915/intel_pm.c |   73 +++++++++++++++++++++++++++++++++++----
 include/drm/audio_drm.h         |   39 +++++++++++++++++++++
 sound/pci/hda/hda_intel.c       |    8 +++++
 3 files changed, 113 insertions(+), 7 deletions(-)
 create mode 100644 include/drm/audio_drm.h

diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
index 2557926..9983f56 100644
--- a/drivers/gpu/drm/i915/intel_pm.c
+++ b/drivers/gpu/drm/i915/intel_pm.c
@@ -4298,18 +4298,12 @@ bool intel_using_power_well(struct drm_device *dev)
 		return true;
 }
 
-void intel_set_power_well(struct drm_device *dev, bool enable)
+void 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;
@@ -4332,6 +4326,71 @@ void intel_set_power_well(struct drm_device *dev, bool enable)
 	}
 }
 
+/* Global drm_device for display audio drvier usage */
+static struct drm_device *power_well_device;
+static bool audio_power_well_using, i915_power_well_using;
+/* Lock protecting power well setting */
+DEFINE_SPINLOCK(powerwell_lock);
+
+void request_power_well(void)
+{
+	DRM_DEBUG_KMS("Display audio requesting power well\n");
+	spin_lock_irq(&powerwell_lock);
+	if (!power_well_device)
+		goto out;
+	if (i915_power_well_using == false)
+		set_power_well(power_well_device, true);
+	audio_power_well_using = true;
+out:
+	spin_unlock_irq(&powerwell_lock);
+	return;
+}
+EXPORT_SYMBOL_GPL(request_power_well);
+
+void release_power_well(void)
+{
+	DRM_DEBUG_KMS("Display audio releasing power well\n");
+	spin_lock_irq(&powerwell_lock);
+	if (!power_well_device)
+		goto out;
+	if (i915_power_well_using == false)
+		set_power_well(power_well_device, false);
+	audio_power_well_using = false;
+out:
+	spin_unlock_irq(&powerwell_lock);
+	return;
+}
+EXPORT_SYMBOL_GPL(release_power_well);
+
+/* TODO: Call this when i915 module unload */
+void remove_power_well(void)
+{
+	spin_lock_irq(&powerwell_lock);
+	audio_power_well_using = false;
+	i915_power_well_using = false;
+	power_well_device = NULL;
+	spin_unlock_irq(&powerwell_lock);
+}
+
+void intel_set_power_well(struct drm_device *dev, bool enable)
+{
+	if (!HAS_POWER_WELL(dev))
+		return;
+
+	spin_lock_irq(&powerwell_lock);
+	power_well_device = dev;
+	i915_power_well_using = enable;
+	if (!enable && audio_power_well_using)
+		goto out;
+
+	if (!i915_disable_power_well && !enable)
+		goto out;
+	set_power_well(dev, enable);
+out:
+	spin_unlock_irq(&powerwell_lock);
+	return;
+}
+
 /*
  * 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/audio_drm.h b/include/drm/audio_drm.h
new file mode 100644
index 0000000..4412b36
--- /dev/null
+++ b/include/drm/audio_drm.h
@@ -0,0 +1,39 @@
+/**************************************************************************
+ *
+ * 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.
+ *
+ *
+ **************************************************************************/
+/*
+ * Authors:
+ * Wang Xingchao <xingchao.wang at intel.com>
+ */
+
+#ifndef _AUDIO_DRM_H_
+#define _AUDIO_DRM_H_
+
+extern void request_power_well(void);
+extern void release_power_well(void);
+
+#endif				/* _AUDIO_DRM_H_ */
diff --git a/sound/pci/hda/hda_intel.c b/sound/pci/hda/hda_intel.c
index 418bfc0..59a85de 100644
--- a/sound/pci/hda/hda_intel.c
+++ b/sound/pci/hda/hda_intel.c
@@ -50,6 +50,7 @@
 #include <linux/clocksource.h>
 #include <linux/time.h>
 #include <linux/completion.h>
+#include <drm/audio_drm.h>
 
 #ifdef CONFIG_X86
 /* for snoop control */
@@ -2869,6 +2870,7 @@ static int azx_suspend(struct device *dev)
 	pci_disable_device(pci);
 	pci_save_state(pci);
 	pci_set_power_state(pci, PCI_D3hot);
+	release_power_well();
 	return 0;
 }
 
@@ -2881,6 +2883,7 @@ static int azx_resume(struct device *dev)
 	if (chip->disabled)
 		return 0;
 
+	request_power_well();
 	pci_set_power_state(pci, PCI_D0);
 	pci_restore_state(pci);
 	if (pci_enable_device(pci) < 0) {
@@ -2913,6 +2916,7 @@ static int azx_runtime_suspend(struct device *dev)
 
 	azx_stop_chip(chip);
 	azx_clear_irq_pending(chip);
+	release_power_well();
 	return 0;
 }
 
@@ -2921,6 +2925,7 @@ static int azx_runtime_resume(struct device *dev)
 	struct snd_card *card = dev_get_drvdata(dev);
 	struct azx *chip = card->private_data;
 
+	request_power_well();
 	azx_init_pci(chip);
 	azx_init_chip(chip, 1);
 	return 0;
@@ -3671,6 +3676,8 @@ static int azx_probe(struct pci_dev *pci,
 		return -ENOENT;
 	}
 
+	request_power_well();
+
 	err = snd_card_create(index[dev], id[dev], THIS_MODULE, 0, &card);
 	if (err < 0) {
 		snd_printk(KERN_ERR "hda-intel: Error creating card!\n");
@@ -3806,6 +3813,7 @@ static void azx_remove(struct pci_dev *pci)
 	if (card)
 		snd_card_free(card);
 	pci_set_drvdata(pci, NULL);
+	release_power_well();
 }
 
 /* PCI IDs */
-- 
1.7.9.5




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