Hi Takashi, > -----Original Message----- > From: Takashi Iwai [mailto:tiwai at suse.de] > Sent: Tuesday, May 14, 2013 8:32 PM > To: Wang Xingchao > Cc: daniel at ffwll.ch; Girdwood, Liam R; alsa-devel at alsa-project.org; Zanoni, > Paulo R; Li, Jocelyn; Lin, Mengdong; intel-gfx at lists.freedesktop.org; Wang, > Xingchao; Barnes, Jesse; david.henningsson at canonical.com > Subject: Re: [alsa-devel] [PATCH 1/2] drm/915: Add private api for power well > usage > > At Tue, 14 May 2013 19:44:18 +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 mobile > > C3 stepping board. > > > > Signed-off-by: Wang Xingchao <xingchao.wang at linux.intel.com> > > --- > > drivers/gpu/drm/i915/intel_pm.c | 76 > +++++++++++++++++++++++++++++++++++---- > > include/drm/i915_powerwell.h | 36 +++++++++++++++++++ > > 2 files changed, 105 insertions(+), 7 deletions(-) create mode > > 100644 include/drm/i915_powerwell.h > > > > diff --git a/drivers/gpu/drm/i915/intel_pm.c > > b/drivers/gpu/drm/i915/intel_pm.c index 0f4b46e..cf7e352 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 enable_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 > +4372,74 @@ > > 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; > > +/* Lock protecting power well setting */ static > > +DEFINE_SPINLOCK(powerwell_lock); static bool i915_power_well_using; > > +static int hsw_power_count; > > + > > +void i915_request_power_well(void) > > +{ > > + if (!power_well_device) > > + return; > > + > > + if (!IS_HASWELL(power_well_device)) > > + return; > > + > > + spin_lock_irq(&powerwell_lock); > > + if (!hsw_power_count++) { > > + enable_power_well(power_well_device, true); > > + } > > Should be > if (!hsw_power_count++ && !i915_power_well_using) > enable_power_well(power_well_device, true); Fixed. Thanks --xingchao
