From a1ad35233345e7ddd9ea3ea7b841432f4723d743 Mon Sep 17 00:00:00 2001 From: Rob Clark Date: Fri, 11 Jul 2014 11:59:22 -0400 Subject: 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 --- drivers/gpu/drm/msm/msm_gpu.c | 3 +++ 1 file changed, 3 insertions(+) (limited to 'drivers/gpu/drm/msm/msm_gpu.c') diff --git a/drivers/gpu/drm/msm/msm_gpu.c b/drivers/gpu/drm/msm/msm_gpu.c index 915240b4b80a..4a0dce587745 100644 --- a/drivers/gpu/drm/msm/msm_gpu.c +++ b/drivers/gpu/drm/msm/msm_gpu.c @@ -612,8 +612,11 @@ int msm_gpu_init(struct drm_device *drm, struct platform_device *pdev, } gpu->id = msm_register_mmu(drm, gpu->mmu); + /* Create ringbuffer: */ + mutex_lock(&drm->struct_mutex); gpu->rb = msm_ringbuffer_new(gpu, ringsz); + mutex_unlock(&drm->struct_mutex); if (IS_ERR(gpu->rb)) { ret = PTR_ERR(gpu->rb); gpu->rb = NULL; -- cgit v1.2.2