Il 22/11/22 15:39, Nícolas F. R. A. Prado ha scritto:
mtk_drm_bind() can fail, in which case drm_dev_put() is called,
destroying the drm_device object. However a pointer to it was still
being held in the private object, and that pointer would be passed along
to DRM in mtk_drm_sys_prepare() if a suspend were triggered at that
point, resulting in a panic. Clean the pointer when destroying the
object in the error path to prevent this from happening.
Fixes: 119f5173628a ("drm/mediatek: Add DRM Driver for Mediatek SoC MT8173.")
Signed-off-by: Nícolas F. R. A. Prado <nfraprado@xxxxxxxxxxxxx>
---
Changes in v2:
- Added Fixes tag
drivers/gpu/drm/mediatek/mtk_drm_drv.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/drivers/gpu/drm/mediatek/mtk_drm_drv.c b/drivers/gpu/drm/mediatek/mtk_drm_drv.c
index 39a42dc8fb85..a21ff1b3258c 100644
--- a/drivers/gpu/drm/mediatek/mtk_drm_drv.c
+++ b/drivers/gpu/drm/mediatek/mtk_drm_drv.c
@@ -514,6 +514,7 @@ static int mtk_drm_bind(struct device *dev)
err_deinit:
mtk_drm_kms_deinit(drm);
err_free:
+ private->drm = NULL;
Sorry for not noticing that in v1, but I've rechecked this function and, while this
commit does indeed actually solve the described issue, I think it's incomplete.
A few lines before, we have a loop that sets
private->all_drm_private[i]->drm = drm;
...so here you should do...
private->drm = NULL;
while (i--) /* a for loop will also do, your choice */
private->all_drm_private[i]->drm = NULL;
That makes sure that you cleanup *everything* :-)
Cheers,
Angelo
