diff options
| author | AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com> | 2025-04-03 12:47:38 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2025-06-19 15:31:39 +0200 |
| commit | 62df1ba66839f9607ca6f0cb2c96493d31011cf2 (patch) | |
| tree | 06937a9f02073e8053b575c66b884ed37e987976 | |
| parent | ad426a7c3ddaed0847e29edce8cd3f91b7cacc32 (diff) | |
drm/mediatek: Fix kobject put for component sub-drivers
[ Upstream commit 80805b62ea5b95eda54c225b989f929ca0691ab0 ]
In function mtk_drm_get_all_drm_priv(), this driver is incrementing
the refcount for the sub-drivers of mediatek-drm with a call to
device_find_child() when taking a reference to all of those child
devices.
When the component bind fails multiple times this results in a
refcount_t overflow, as the reference count is never decremented:
fix that by adding a call to put_device() for all of the mmsys
devices in a loop, in error cases of mtk_drm_bind() and in the
mtk_drm_unbind() callback.
Fixes: 1ef7ed48356c ("drm/mediatek: Modify mediatek-drm for mt8195 multi mmsys support")
Reviewed-by: Chen-Yu Tsai <wenst@chromium.org>
Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Link: https://patchwork.kernel.org/project/dri-devel/patch/20250403104741.71045-3-angelogioacchino.delregno@collabora.com/
Signed-off-by: Chun-Kuang Hu <chunkuang.hu@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
| -rw-r--r-- | drivers/gpu/drm/mediatek/mtk_drm_drv.c | 9 |
1 files changed, 9 insertions, 0 deletions
diff --git a/drivers/gpu/drm/mediatek/mtk_drm_drv.c b/drivers/gpu/drm/mediatek/mtk_drm_drv.c index 86541b0d5c49..3cdda6694f7f 100644 --- a/drivers/gpu/drm/mediatek/mtk_drm_drv.c +++ b/drivers/gpu/drm/mediatek/mtk_drm_drv.c @@ -675,6 +675,10 @@ err_free: for (i = 0; i < private->data->mmsys_dev_num; i++) private->all_drm_private[i]->drm = NULL; err_put_dev: + for (i = 0; i < private->data->mmsys_dev_num; i++) { + /* For device_find_child in mtk_drm_get_all_priv() */ + put_device(private->all_drm_private[i]->dev); + } put_device(private->mutex_dev); return ret; } @@ -682,6 +686,7 @@ err_put_dev: static void mtk_drm_unbind(struct device *dev) { struct mtk_drm_private *private = dev_get_drvdata(dev); + int i; /* for multi mmsys dev, unregister drm dev in mmsys master */ if (private->drm_master) { @@ -689,6 +694,10 @@ static void mtk_drm_unbind(struct device *dev) mtk_drm_kms_deinit(private->drm); drm_dev_put(private->drm); + for (i = 0; i < private->data->mmsys_dev_num; i++) { + /* For device_find_child in mtk_drm_get_all_priv() */ + put_device(private->all_drm_private[i]->dev); + } put_device(private->mutex_dev); } private->mtk_drm_bound = false; |