diff options
Diffstat (limited to 'target/linux/brcm2708/patches-4.4/0097-drm-vc4-Drop-struct_mutex-around-CL-validation.patch')
| -rw-r--r-- | target/linux/brcm2708/patches-4.4/0097-drm-vc4-Drop-struct_mutex-around-CL-validation.patch | 74 |
1 files changed, 74 insertions, 0 deletions
diff --git a/target/linux/brcm2708/patches-4.4/0097-drm-vc4-Drop-struct_mutex-around-CL-validation.patch b/target/linux/brcm2708/patches-4.4/0097-drm-vc4-Drop-struct_mutex-around-CL-validation.patch new file mode 100644 index 0000000000..5275fb5e17 --- /dev/null +++ b/target/linux/brcm2708/patches-4.4/0097-drm-vc4-Drop-struct_mutex-around-CL-validation.patch @@ -0,0 +1,74 @@ +From 4cc42228e828c8cba5e2f712fd92fe3e0bb8b09d Mon Sep 17 00:00:00 2001 +From: Eric Anholt <eric@anholt.net> +Date: Mon, 19 Oct 2015 08:44:35 -0700 +Subject: [PATCH 097/127] drm/vc4: Drop struct_mutex around CL validation. + +We were using it so that we could make sure that shader validation +state didn't change while we were validating, but now shader +validation state is immutable. The bcl/rcl generation doesn't do any +other BO dereferencing, and seems to have no other global state +dependency not covered by job_lock / bo_lock. We only need to hold +struct_mutex for object unreferencing. + +Fixes a lock order reversal between mmap_sem and struct_mutex. + +Signed-off-by: Eric Anholt <eric@anholt.net> +--- + drivers/gpu/drm/vc4/vc4_gem.c | 13 ++++++------- + 1 file changed, 6 insertions(+), 7 deletions(-) + +--- a/drivers/gpu/drm/vc4/vc4_gem.c ++++ b/drivers/gpu/drm/vc4/vc4_gem.c +@@ -439,10 +439,12 @@ fail: + } + + static void +-vc4_complete_exec(struct vc4_exec_info *exec) ++vc4_complete_exec(struct drm_device *dev, struct vc4_exec_info *exec) + { + unsigned i; + ++ /* Need the struct lock for drm_gem_object_unreference(). */ ++ mutex_lock(&dev->struct_mutex); + if (exec->bo) { + for (i = 0; i < exec->bo_count; i++) + drm_gem_object_unreference(&exec->bo[i].bo->base); +@@ -455,6 +457,7 @@ vc4_complete_exec(struct vc4_exec_info * + list_del(&bo->unref_head); + drm_gem_object_unreference(&bo->base.base); + } ++ mutex_unlock(&dev->struct_mutex); + + kfree(exec); + } +@@ -473,7 +476,7 @@ vc4_job_handle_completed(struct vc4_dev + list_del(&exec->head); + + spin_unlock_irqrestore(&vc4->job_lock, irqflags); +- vc4_complete_exec(exec); ++ vc4_complete_exec(vc4->dev, exec); + spin_lock_irqsave(&vc4->job_lock, irqflags); + } + +@@ -525,12 +528,8 @@ vc4_job_done_work(struct work_struct *wo + { + struct vc4_dev *vc4 = + container_of(work, struct vc4_dev, job_done_work); +- struct drm_device *dev = vc4->dev; + +- /* Need the struct lock for drm_gem_object_unreference(). */ +- mutex_lock(&dev->struct_mutex); + vc4_job_handle_completed(vc4); +- mutex_unlock(&dev->struct_mutex); + } + + static int +@@ -639,7 +638,7 @@ vc4_submit_cl_ioctl(struct drm_device *d + return 0; + + fail: +- vc4_complete_exec(exec); ++ vc4_complete_exec(vc4->dev, exec); + + return ret; + } |