> -----Original Message----- > From: Takashi Iwai [mailto:tiwai at suse.de] > Sent: Tuesday, May 21, 2013 3:18 PM > To: Wang Xingchao > Cc: daniel at ffwll.ch; Girdwood, Liam R; david.henningsson at canonical.com; Lin, > Mengdong; Li, Jocelyn; alsa-devel at alsa-project.org; > intel-gfx at 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 at 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 > >
