[Intel-gfx] [PATCH 04/11] drm/i915: Added is_intel_rpm_allowed helper

[Tangudu, Tilak]

> -----Original Message-----
> From: Gupta, Anshuman <anshuman.gupta at intel.com>
> Sent: Tuesday, June 21, 2022 7:47 PM
> To: Tangudu, Tilak <tilak.tangudu at intel.com>; intel-gfx at lists.freedesktop.org;
> Ewins, Jon <jon.ewins at intel.com>; Vivi, Rodrigo <rodrigo.vivi at intel.com>;
> Belgaumkar, Vinay <vinay.belgaumkar at intel.com>; Wilson, Chris P
> <chris.p.wilson at intel.com>; Dixit, Ashutosh <ashutosh.dixit at intel.com>;
> Nilawar, Badal <badal.nilawar at intel.com>; Roper, Matthew D
> <matthew.d.roper at intel.com>; Gupta, saurabhg
> <saurabhg.gupta at intel.com>; Iddamsetty, Aravind
> <aravind.iddamsetty at intel.com>; Sundaresan, Sujaritha
> <sujaritha.sundaresan at intel.com>
> Subject: RE: [PATCH 04/11] drm/i915: Added is_intel_rpm_allowed helper
> 
> 
> 
> > -----Original Message-----
> > From: Tangudu, Tilak <tilak.tangudu at intel.com>
> > Sent: Tuesday, June 21, 2022 6:05 PM
> > To: intel-gfx at lists.freedesktop.org; Ewins, Jon <jon.ewins at intel.com>;
> > Vivi, Rodrigo <rodrigo.vivi at intel.com>; Belgaumkar, Vinay
> > <vinay.belgaumkar at intel.com>; Wilson, Chris P
> > <chris.p.wilson at intel.com>; Dixit, Ashutosh
> > <ashutosh.dixit at intel.com>; Nilawar, Badal <badal.nilawar at intel.com>;
> > Gupta, Anshuman <anshuman.gupta at intel.com>; Tangudu, Tilak
> > <tilak.tangudu at intel.com>; Roper, Matthew D
> > <matthew.d.roper at intel.com>; Gupta, saurabhg
> > <saurabhg.gupta at intel.com>; Iddamsetty, Aravind
> > <aravind.iddamsetty at intel.com>; Sundaresan, Sujaritha
> > <sujaritha.sundaresan at intel.com>
> > Subject: [PATCH 04/11] drm/i915: Added is_intel_rpm_allowed helper
> >
> > Added is_intel_rpm_allowed function to query the runtime_pm status and
> > disllow during suspending and resuming.
> This seems a hack,
> Not sure if we have better way to handle it.
> May be check this in intel_pm_runtime_{get,put} to keep entire code simple ?
Yes, that would be simple without code refactoring.
Checked the same with Chris, he suggested unbalancing of wakeref might popup
If used at intel_pm_runtime_{get,put}  . So used like this,
 @Wilson, Chris P , Please comment .
@Vivi, Rodrigo , Any suggestion ?
 
> >
> > Signed-off-by: Tilak Tangudu <tilak.tangudu at intel.com>
> > ---
> >  drivers/gpu/drm/i915/intel_runtime_pm.c | 15 +++++++++++++++
> > drivers/gpu/drm/i915/intel_runtime_pm.h |  1 +
> >  2 files changed, 16 insertions(+)
> >
> > diff --git a/drivers/gpu/drm/i915/intel_runtime_pm.c
> > b/drivers/gpu/drm/i915/intel_runtime_pm.c
> > index 6ed5786bcd29..3759a8596084 100644
> > --- a/drivers/gpu/drm/i915/intel_runtime_pm.c
> > +++ b/drivers/gpu/drm/i915/intel_runtime_pm.c
> > @@ -320,6 +320,21 @@ untrack_all_intel_runtime_pm_wakerefs(struct
> > intel_runtime_pm *rpm)  }
> >
> >  #endif
> > +static int intel_runtime_pm_status(struct intel_runtime_pm *rpm) {
> > +return rpm->kdev->power.runtime_status; }
> This is racy in principal, we need a kdev->power lock here.
> Regards,
> Anshuman Gupta.
> > +
> > +bool is_intel_rpm_allowed(struct intel_runtime_pm *rpm) { int
> > +rpm_status;
> > +
> > +rpm_status = intel_runtime_pm_status(rpm); if (rpm_status ==
> > +RPM_RESUMING || rpm_status ==
> > RPM_SUSPENDING)
> > +return false;
> > +else
> > +return true;
> > +}
> >
> >  static void
> >  intel_runtime_pm_acquire(struct intel_runtime_pm *rpm, bool wakelock)
> > diff -- git a/drivers/gpu/drm/i915/intel_runtime_pm.h
> > b/drivers/gpu/drm/i915/intel_runtime_pm.h
> > index d9160e3ff4af..99418c3a934a 100644
> > --- a/drivers/gpu/drm/i915/intel_runtime_pm.h
> > +++ b/drivers/gpu/drm/i915/intel_runtime_pm.h
> > @@ -173,6 +173,7 @@ void intel_runtime_pm_init_early(struct
> > intel_runtime_pm *rpm);  void intel_runtime_pm_enable(struct
> > intel_runtime_pm *rpm);  void intel_runtime_pm_disable(struct
> > intel_runtime_pm *rpm);  void intel_runtime_pm_driver_release(struct
> > intel_runtime_pm *rpm);
> > +bool is_intel_rpm_allowed(struct intel_runtime_pm *rpm);
> >
> >  intel_wakeref_t intel_runtime_pm_get(struct intel_runtime_pm *rpm);
> > intel_wakeref_t intel_runtime_pm_get_if_in_use(struct intel_runtime_pm
> > *rpm);
> > --
> > 2.25.1
>