-----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