2020-08-14 08:31:47

by 赵军奎

Subject: [PATCH] drm/via: reduce no need mutex_lock area

In function via_mem_alloc`s error branch, DRM_ERROR is protected
in the mutex_lock(&dev->struct_mutex) area.
From the code, we see that DRM_ERROR is just an error log print
without any struct element, there is no need to protect this.

Signed-off-by: Bernard Zhao <[email protected]>
---
drivers/gpu/drm/via/via_mm.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/via/via_mm.c b/drivers/gpu/drm/via/via_mm.c
index 45cc9e900260..dae1bacd86c1 100644
--- a/drivers/gpu/drm/via/via_mm.c
+++ b/drivers/gpu/drm/via/via_mm.c
@@ -129,9 +129,9 @@ int via_mem_alloc(struct drm_device *dev, void *data,
mutex_lock(&dev->struct_mutex);
if (0 == ((mem->type == VIA_MEM_VIDEO) ? dev_priv->vram_initialized :
dev_priv->agp_initialized)) {
+ mutex_unlock(&dev->struct_mutex);
DRM_ERROR
("Attempt to allocate from uninitialized memory manager.\n");
- mutex_unlock(&dev->struct_mutex);
return -EINVAL;
}

--
2.26.2

2020-10-17 10:47:04

by Sam Ravnborg

Subject: Re: [PATCH] drm/via: reduce no need mutex_lock area

Hi Bernard.

On Fri, Aug 14, 2020 at 01:30:19AM -0700, Bernard Zhao wrote:
> In function via_mem_alloc`s error branch, DRM_ERROR is protected
> in the mutex_lock(&dev->struct_mutex) area.
> >From the code, we see that DRM_ERROR is just an error log print
> without any struct element, there is no need to protect this.
>
> Signed-off-by: Bernard Zhao <[email protected]>

Thanks, applied to drm-misc-next.

The patch will show up in -next in a few weeks.

Sam