Re: [PATCH] drm/rockchip: gem: add the lacks lock and trivial changes

From: Mark yao
Date: Tue May 30 2017 - 22:24:49 EST


On 2017å05æ31æ 10:14, Caesar Wang wrote:
As the allocation and free buffer that need to add mutex lock for drm mm,
but it lacks the locking on error path in rockchip_gem_iommu_map().
Also, the trivial changes like The comment should be placed in the
kerneldoc and unused blank line.

Signed-off-by: Caesar Wang <wxt@xxxxxxxxxxxxxx>

Looks good.

Reviewed-by: Mark Yao <mark.yao@xxxxxxxxxxxxxx>

---

drivers/gpu/drm/rockchip/rockchip_drm_drv.h | 2 +-
drivers/gpu/drm/rockchip/rockchip_drm_gem.c | 5 +++--
2 files changed, 4 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/rockchip/rockchip_drm_drv.h b/drivers/gpu/drm/rockchip/rockchip_drm_drv.h
index 47905fa..c7e96b8 100644
--- a/drivers/gpu/drm/rockchip/rockchip_drm_drv.h
+++ b/drivers/gpu/drm/rockchip/rockchip_drm_drv.h
@@ -45,13 +45,13 @@ struct rockchip_crtc_state {
*
* @crtc: array of enabled CRTCs, used to map from "pipe" to drm_crtc.
* @num_pipe: number of pipes for this device.
+ * @mm_lock: protect drm_mm on multi-threads.
*/
struct rockchip_drm_private {
struct drm_fb_helper fbdev_helper;
struct drm_gem_object *fbdev_bo;
struct drm_atomic_state *state;
struct iommu_domain *domain;
- /* protect drm_mm on multi-threads */
struct mutex mm_lock;
struct drm_mm mm;
struct list_head psr_list;
diff --git a/drivers/gpu/drm/rockchip/rockchip_drm_gem.c b/drivers/gpu/drm/rockchip/rockchip_drm_gem.c
index df9e570..b74ac71 100644
--- a/drivers/gpu/drm/rockchip/rockchip_drm_gem.c
+++ b/drivers/gpu/drm/rockchip/rockchip_drm_gem.c
@@ -29,12 +29,11 @@ static int rockchip_gem_iommu_map(struct rockchip_gem_object *rk_obj)
ssize_t ret;
mutex_lock(&private->mm_lock);
-
ret = drm_mm_insert_node_generic(&private->mm, &rk_obj->mm,
rk_obj->base.size, PAGE_SIZE,
0, 0);
-
mutex_unlock(&private->mm_lock);
+
if (ret < 0) {
DRM_ERROR("out of I/O virtual memory: %zd\n", ret);
return ret;
@@ -56,7 +55,9 @@ static int rockchip_gem_iommu_map(struct rockchip_gem_object *rk_obj)
return 0;
err_remove_node:
+ mutex_lock(&private->mm_lock);
drm_mm_remove_node(&rk_obj->mm);
+ mutex_unlock(&private->mm_lock);
return ret;
}


--
ïark Yao