From 5ab57c7020697942ea15f45ad14c69cecb164329 Mon Sep 17 00:00:00 2001 From: Chris Wilson Date: Fri, 15 Jul 2016 14:56:20 +0100 Subject: [PATCH] drm/i915: Flush logical context image out to memory upon suspend MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit Before suspend, and especially before building the hibernation image, we need to context image to be coherent in memory. To do this we require that we perform a context switch to a disposable context (i.e. the dev_priv->kernel_context) - when that switch is complete, all other context images will be complete. This leaves the kernel_context image as incomplete, but fortunately that is disposable and we can do a quick fixup of the logical state after resuming. v2: Share the nearly identical code to switch to the kernel context with eviction. v3: Explain why we need the switch and reset. Testcase: igt/gem_exec_suspend # bsw References: https://bugs.freedesktop.org/show_bug.cgi?id=96526 Signed-off-by: Chris Wilson Cc: Ville Syrjälä Reviewed-by: Ville Syrjälä Tested-by: Ville Syrjälä Link: http://patchwork.freedesktop.org/patch/msgid/1468590980-6186-2-git-send-email-chris@chris-wilson.co.uk --- drivers/gpu/drm/i915/i915_drv.c | 4 +--- drivers/gpu/drm/i915/i915_drv.h | 1 + drivers/gpu/drm/i915/i915_gem.c | 35 +++++++++++++++++++++++++++++++++ 3 files changed, 37 insertions(+), 3 deletions(-) diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c index 15440123e38d..c5b7b8e0678a 100644 --- a/drivers/gpu/drm/i915/i915_drv.c +++ b/drivers/gpu/drm/i915/i915_drv.c @@ -1590,9 +1590,7 @@ static int i915_drm_resume(struct drm_device *dev) intel_csr_ucode_resume(dev_priv); - mutex_lock(&dev->struct_mutex); - i915_gem_restore_gtt_mappings(dev); - mutex_unlock(&dev->struct_mutex); + i915_gem_resume(dev); i915_restore_state(dev); intel_opregion_setup(dev_priv); diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h index cd1ccc47ee8b..27d9b2c374b3 100644 --- a/drivers/gpu/drm/i915/i915_drv.h +++ b/drivers/gpu/drm/i915/i915_drv.h @@ -3384,6 +3384,7 @@ void i915_gem_init_swizzling(struct drm_device *dev); void i915_gem_cleanup_engines(struct drm_device *dev); int __must_check i915_gem_wait_for_idle(struct drm_i915_private *dev_priv); int __must_check i915_gem_suspend(struct drm_device *dev); +void i915_gem_resume(struct drm_device *dev); void __i915_add_request(struct drm_i915_gem_request *req, struct drm_i915_gem_object *batch_obj, bool flush_caches); diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c index cf0e8aa8035c..4644a7e67cf6 100644 --- a/drivers/gpu/drm/i915/i915_gem.c +++ b/drivers/gpu/drm/i915/i915_gem.c @@ -4983,12 +4983,30 @@ i915_gem_suspend(struct drm_device *dev) intel_suspend_gt_powersave(dev_priv); mutex_lock(&dev->struct_mutex); + + /* We have to flush all the executing contexts to main memory so + * that they can saved in the hibernation image. To ensure the last + * context image is coherent, we have to switch away from it. That + * leaves the dev_priv->kernel_context still active when + * we actually suspend, and its image in memory may not match the GPU + * state. Fortunately, the kernel_context is disposable and we do + * not rely on its state. + */ + ret = i915_gem_switch_to_kernel_context(dev_priv); + if (ret) + goto err; + ret = i915_gem_wait_for_idle(dev_priv); if (ret) goto err; i915_gem_retire_requests(dev_priv); + /* Note that rather than stopping the engines, all we have to do + * is assert that every RING_HEAD == RING_TAIL (all execution complete) + * and similar for all logical context images (to ensure they are + * all ready for hibernation). + */ i915_gem_stop_engines(dev); i915_gem_context_lost(dev_priv); mutex_unlock(&dev->struct_mutex); @@ -5009,6 +5027,23 @@ err: return ret; } +void i915_gem_resume(struct drm_device *dev) +{ + struct drm_i915_private *dev_priv = to_i915(dev); + + mutex_lock(&dev->struct_mutex); + i915_gem_restore_gtt_mappings(dev); + + /* As we didn't flush the kernel context before suspend, we cannot + * guarantee that the context image is complete. So let's just reset + * it and start again. + */ + if (i915.enable_execlists) + intel_lr_context_reset(dev_priv, dev_priv->kernel_context); + + mutex_unlock(&dev->struct_mutex); +} + void i915_gem_init_swizzling(struct drm_device *dev) { struct drm_i915_private *dev_priv = to_i915(dev); -- 2.20.1