From aabee1bbc11db3f7238e0fef8f1bf280920f98f4 Mon Sep 17 00:00:00 2001 From: Imre Deak Date: Tue, 15 Dec 2015 20:10:29 +0200 Subject: [PATCH] drm/i915: clarify comment about mandatory RPM put/get during driver load/unload Signed-off-by: Imre Deak Reviewed-by: Joonas Lahtinen Link: http://patchwork.freedesktop.org/patch/msgid/1450203038-5150-2-git-send-email-imre.deak@intel.com --- drivers/gpu/drm/i915/intel_runtime_pm.c | 15 +++++++++++++-- 1 file changed, 13 insertions(+), 2 deletions(-) diff --git a/drivers/gpu/drm/i915/intel_runtime_pm.c b/drivers/gpu/drm/i915/intel_runtime_pm.c index 2c2151f1c47e..9945040fa45f 100644 --- a/drivers/gpu/drm/i915/intel_runtime_pm.c +++ b/drivers/gpu/drm/i915/intel_runtime_pm.c @@ -1975,9 +1975,15 @@ int intel_power_domains_init(struct drm_i915_private *dev_priv) */ void intel_power_domains_fini(struct drm_i915_private *dev_priv) { - /* The i915.ko module is still not prepared to be loaded when + /* + * The i915.ko module is still not prepared to be loaded when * the power well is not enabled, so just enable it in case - * we're going to unload/reload. */ + * we're going to unload/reload. + * The following also reacquires the RPM reference the core passed + * to the driver during loading, which is dropped in + * intel_runtime_pm_enable(). We have to hand back the control of the + * device to the core with this reference held. + */ intel_display_set_init_power(dev_priv, true); /* Remove the refcount we took to keep power well support disabled. */ @@ -2313,6 +2319,11 @@ void intel_runtime_pm_enable(struct drm_i915_private *dev_priv) pm_runtime_mark_last_busy(device); pm_runtime_use_autosuspend(device); + /* + * The core calls the driver load handler with an RPM reference held. + * We drop that here and will reacquire it during unloading in + * intel_power_domains_fini(). + */ pm_runtime_put_autosuspend(device); } -- 2.20.1