On ti, 2015-11-17 at 13:46 +0100, Patrik Jakobsson wrote:
> On Wed, Nov 11, 2015 at 07:03:54PM +0200, Imre Deak wrote:
> > When this option is 0 (so the power well support is disabled) we are
> > supposed to enable all power wells once and don't disable them unless we
> > system suspend the device. Currently if the option is 0, we can call the
> > power well enable handlers multiple times, whenever their refcount
> > changes from 0->1. This may not be a problem for the HW, but it's not
> > logical and may trigger some warnings in the power well code which
> > doesn't expect this. So simply keep around a reference while we are
> > not system suspended to solve this. For simplicity mark the module
> > option read only, so we don't need to deal with re-enabling the feature
> > during runtime. If someone really needs that it could be added later in
> > a more proper way.
> >
> > Signed-off-by: Imre Deak <imre.deak@xxxxxxxxx>
> > ---
> > drivers/gpu/drm/i915/i915_params.c | 2 +-
> > drivers/gpu/drm/i915/intel_runtime_pm.c | 16 +++++++++++++++-
> > 2 files changed, 16 insertions(+), 2 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/i915/i915_params.c b/drivers/gpu/drm/i915/i915_params.c
> > index 7cf7474..2b36e67 100644
> > --- a/drivers/gpu/drm/i915/i915_params.c
> > +++ b/drivers/gpu/drm/i915/i915_params.c
> > @@ -131,7 +131,7 @@ module_param_named_unsafe(preliminary_hw_support, i915.preliminary_hw_support, i
> > MODULE_PARM_DESC(preliminary_hw_support,
> > "Enable preliminary hardware support.");
> >
> > -module_param_named_unsafe(disable_power_well, i915.disable_power_well, int, 0600);
> > +module_param_named_unsafe(disable_power_well, i915.disable_power_well, int, 0400);
> > MODULE_PARM_DESC(disable_power_well,
> > "Disable display power wells when possible "
> > "(-1=auto [default], 0=power wells always on, 1=power wells disabled when possible)");
> > diff --git a/drivers/gpu/drm/i915/intel_runtime_pm.c b/drivers/gpu/drm/i915/intel_runtime_pm.c
> > index b33969b..d167a45 100644
> > --- a/drivers/gpu/drm/i915/intel_runtime_pm.c
> > +++ b/drivers/gpu/drm/i915/intel_runtime_pm.c
> > @@ -1427,7 +1427,7 @@ void intel_display_power_put(struct drm_i915_private *dev_priv,
> > for_each_power_well_rev(i, power_well, BIT(domain), power_domains) {
> > WARN_ON(!power_well->count);
> >
> > - if (!--power_well->count && i915.disable_power_well)
> > + if (!--power_well->count)
> > intel_power_well_disable(dev_priv, power_well);
> > }
> >
> > @@ -1899,6 +1899,10 @@ void intel_power_domains_fini(struct drm_i915_private *dev_priv)
> > * the power well is not enabled, so just enable it in case
> > * we're going to unload/reload. */
> > intel_display_set_init_power(dev_priv, true);
> > +
> > + /* Remove the refcount we took to keep power well support disabled. */
> > + if (!i915.disable_power_well)
> > + intel_display_power_put(dev_priv, POWER_DOMAIN_INIT);
> > }
> >
> > static void intel_power_domains_sync_hw(struct drm_i915_private *dev_priv)
> > @@ -2099,6 +2103,9 @@ void intel_power_domains_init_hw(struct drm_i915_private *dev_priv, bool resume)
> >
> > /* For now, we need the power well to be always enabled. */
> > intel_display_set_init_power(dev_priv, true);
> > + /* Disable power support if the user asked so. */
> > + if (!i915.disable_power_well)
> > + intel_display_power_get(dev_priv, POWER_DOMAIN_INIT);
> > intel_power_domains_sync_hw(dev_priv);
> > power_domains->initializing = false;
> > }
> > @@ -2114,6 +2121,13 @@ void intel_power_domains_suspend(struct drm_i915_private *dev_priv)
> > {
> > if (IS_SKYLAKE(dev_priv) || IS_KABYLAKE(dev_priv))
> > skl_display_core_uninit(dev_priv);
> > +
> > + /*
> > + * Even if power well support was disabled we still want to disabled
> > + * we want to disable the power wells while we are system suspended.
> > + */
>
> This comment needs fixing. With that done:
>
> Reviewed-by: Patrik Jakobsson <patrik.jakobsson@xxxxxxxxxxxxxxx>
Pushed to dinq, thanks for the review.
>
> > + if (!i915.disable_power_well)
> > + intel_display_power_put(dev_priv, POWER_DOMAIN_INIT);
> > }
> >
> > /**
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