drm/msm: fix potential deadlock in gpu init
Somewhere along the way, the firmware loader sprouted another lock
dependency, resulting in possible deadlock scenario:
&dev->struct_mutex --> &sb->s_type->i_mutex_key#2 --> &mm->mmap_sem
which is problematic vs things like gem mmap.
So introduce a separate mutex to synchronize gpu init.
Signed-off-by: Rob Clark <robdclark@gmail.com>
diff --git a/drivers/gpu/drm/msm/adreno/adreno_gpu.c b/drivers/gpu/drm/msm/adreno/adreno_gpu.c
index 76c1df7..655ce5b 100644
--- a/drivers/gpu/drm/msm/adreno/adreno_gpu.c
+++ b/drivers/gpu/drm/msm/adreno/adreno_gpu.c
@@ -95,7 +95,7 @@
DBG("%s", gpu->name);
- ret = msm_gem_get_iova_locked(gpu->rb->bo, gpu->id, &gpu->rb_iova);
+ ret = msm_gem_get_iova(gpu->rb->bo, gpu->id, &gpu->rb_iova);
if (ret) {
gpu->rb_iova = 0;
dev_err(gpu->dev->dev, "could not map ringbuffer: %d\n", ret);
@@ -370,8 +370,10 @@
return ret;
}
+ mutex_lock(&drm->struct_mutex);
gpu->memptrs_bo = msm_gem_new(drm, sizeof(*gpu->memptrs),
MSM_BO_UNCACHED);
+ mutex_unlock(&drm->struct_mutex);
if (IS_ERR(gpu->memptrs_bo)) {
ret = PTR_ERR(gpu->memptrs_bo);
gpu->memptrs_bo = NULL;
@@ -379,13 +381,13 @@
return ret;
}
- gpu->memptrs = msm_gem_vaddr_locked(gpu->memptrs_bo);
+ gpu->memptrs = msm_gem_vaddr(gpu->memptrs_bo);
if (!gpu->memptrs) {
dev_err(drm->dev, "could not vmap memptrs\n");
return -ENOMEM;
}
- ret = msm_gem_get_iova_locked(gpu->memptrs_bo, gpu->base.id,
+ ret = msm_gem_get_iova(gpu->memptrs_bo, gpu->base.id,
&gpu->memptrs_iova);
if (ret) {
dev_err(drm->dev, "could not map memptrs: %d\n", ret);