diff options
| author | Rob Clark <robdclark@gmail.com> | 2014-07-11 11:59:22 -0400 |
|---|---|---|
| committer | Rob Clark <robdclark@gmail.com> | 2014-08-04 11:55:29 -0400 |
| commit | a1ad35233345e7ddd9ea3ea7b841432f4723d743 (patch) | |
| tree | 89fa09c7bfbf0367280bd998c0dfc4508b205776 /drivers/gpu/drm/msm/msm_drv.c | |
| parent | 944fc36c31ed685cf8d3d125eb681ae7198f06fc (diff) | |
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>
Diffstat (limited to 'drivers/gpu/drm/msm/msm_drv.c')
| -rw-r--r-- | drivers/gpu/drm/msm/msm_drv.c | 13 |
1 files changed, 8 insertions, 5 deletions
diff --git a/drivers/gpu/drm/msm/msm_drv.c b/drivers/gpu/drm/msm/msm_drv.c index a2f5bf6da6f3..b447c01ad89c 100644 --- a/drivers/gpu/drm/msm/msm_drv.c +++ b/drivers/gpu/drm/msm/msm_drv.c @@ -181,7 +181,6 @@ static int msm_load(struct drm_device *dev, unsigned long flags) struct msm_kms *kms; int ret; - priv = kzalloc(sizeof(*priv), GFP_KERNEL); if (!priv) { dev_err(dev->dev, "failed to allocate private data\n"); @@ -314,13 +313,15 @@ fail: static void load_gpu(struct drm_device *dev) { + static DEFINE_MUTEX(init_lock); struct msm_drm_private *priv = dev->dev_private; struct msm_gpu *gpu; + mutex_lock(&init_lock); + if (priv->gpu) - return; + goto out; - mutex_lock(&dev->struct_mutex); gpu = a3xx_gpu_init(dev); if (IS_ERR(gpu)) { dev_warn(dev->dev, "failed to load a3xx gpu\n"); @@ -330,7 +331,9 @@ static void load_gpu(struct drm_device *dev) if (gpu) { int ret; + mutex_lock(&dev->struct_mutex); gpu->funcs->pm_resume(gpu); + mutex_unlock(&dev->struct_mutex); ret = gpu->funcs->hw_init(gpu); if (ret) { dev_err(dev->dev, "gpu hw init failed: %d\n", ret); @@ -340,12 +343,12 @@ static void load_gpu(struct drm_device *dev) /* give inactive pm a chance to kick in: */ msm_gpu_retire(gpu); } - } priv->gpu = gpu; - mutex_unlock(&dev->struct_mutex); +out: + mutex_unlock(&init_lock); } static int msm_open(struct drm_device *dev, struct drm_file *file) |