From 0606035fcab6b2630b0d95a5b31e235ec9ad5642 Mon Sep 17 00:00:00 2001 From: Chris Wilson Date: Thu, 31 May 2018 09:22:44 +0100 Subject: [PATCH] drm/i915: "Race-to-idle" after switching to the kernel context During suspend we want to flush out all active contexts and their rendering. To do so we queue a request from the kernel's context, once we know that request is done, we know the GPU is completely idle. To speed up that switch bump the GPU clocks. Switching to the kernel context prior to idling is also used to enforce a barrier before changing OA properties, and when evicting active rendering from the global GTT. All cases where we do want to race-to-idle. v2: Limit the boosting to only the switch before suspend. v3: Limit it to the wait-for-idle on suspend. Signed-off-by: Chris Wilson Cc: David Weinehall Cc: Mika Kuoppala Tested-by: David Weinehall #v1 Reviewed-by: Mika Kuoppala Link: https://patchwork.freedesktop.org/patch/msgid/20180531082246.9763-2-chris@chris-wilson.co.uk --- drivers/gpu/drm/i915/i915_gem.c | 27 +++++++++++++++++++++++++-- drivers/gpu/drm/i915/i915_request.h | 1 + 2 files changed, 26 insertions(+), 2 deletions(-) diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c index 173d1e4ad963..b312ac006d24 100644 --- a/drivers/gpu/drm/i915/i915_gem.c +++ b/drivers/gpu/drm/i915/i915_gem.c @@ -3708,7 +3708,29 @@ i915_gem_wait_ioctl(struct drm_device *dev, void *data, struct drm_file *file) static int wait_for_timeline(struct i915_timeline *tl, unsigned int flags) { - return i915_gem_active_wait(&tl->last_request, flags); + struct i915_request *rq; + long ret; + + rq = i915_gem_active_get_unlocked(&tl->last_request); + if (!rq) + return 0; + + /* + * "Race-to-idle". + * + * Switching to the kernel context is often used a synchronous + * step prior to idling, e.g. in suspend for flushing all + * current operations to memory before sleeping. These we + * want to complete as quickly as possible to avoid prolonged + * stalls, so allow the gpu to boost to maximum clocks. + */ + if (flags & I915_WAIT_FOR_IDLE_BOOST) + gen6_rps_boost(rq, NULL); + + ret = i915_request_wait(rq, flags, MAX_SCHEDULE_TIMEOUT); + i915_request_put(rq); + + return ret < 0 ? ret : 0; } static int wait_for_engines(struct drm_i915_private *i915) @@ -4983,7 +5005,8 @@ int i915_gem_suspend(struct drm_i915_private *dev_priv) ret = i915_gem_wait_for_idle(dev_priv, I915_WAIT_INTERRUPTIBLE | - I915_WAIT_LOCKED); + I915_WAIT_LOCKED | + I915_WAIT_FOR_IDLE_BOOST); if (ret && ret != -EIO) goto err_unlock; diff --git a/drivers/gpu/drm/i915/i915_request.h b/drivers/gpu/drm/i915/i915_request.h index 1bbbb7a9fa03..491ff81d0fea 100644 --- a/drivers/gpu/drm/i915/i915_request.h +++ b/drivers/gpu/drm/i915/i915_request.h @@ -267,6 +267,7 @@ long i915_request_wait(struct i915_request *rq, #define I915_WAIT_INTERRUPTIBLE BIT(0) #define I915_WAIT_LOCKED BIT(1) /* struct_mutex held, handle GPU reset */ #define I915_WAIT_ALL BIT(2) /* used by i915_gem_object_wait() */ +#define I915_WAIT_FOR_IDLE_BOOST BIT(3) static inline u32 intel_engine_get_seqno(struct intel_engine_cs *engine);