6.6-stable review patch. If anyone has any objections, please let me know.
------------------
From: Michael Walle <mwalle@xxxxxxxxxx>
[ Upstream commit 4662817aed5a9d6c695658d0105d8ff4b84ac6cb ]
drm_crtc_from_index(0) might return NULL if there are no CRTCs
registered at all which will lead to a kernel oops in
mtk_drm_crtc_dma_dev_get(). Add the missing return value check.
Fixes: 0d9eee9118b7 ("drm/mediatek: Add drm ovl_adaptor sub driver for MT8195")
Signed-off-by: Michael Walle <mwalle@xxxxxxxxxx>
Reviewed-by: Nícolas F. R. A. Prado <nfraprado@xxxxxxxxxxxxx>
Tested-by: Nícolas F. R. A. Prado <nfraprado@xxxxxxxxxxxxx>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@xxxxxxxxxxxxx>
Tested-by: Eugen Hristev <eugen.hristev@xxxxxxxxxxxxx>
Reviewed-by: Eugen Hristev <eugen.hristev@xxxxxxxxxxxxx>
Link: https://patchwork.kernel.org/project/dri-devel/patch/20230905084922.3908121-1-mwalle@xxxxxxxxxx/
Signed-off-by: Chun-Kuang Hu <chunkuang.hu@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/gpu/drm/mediatek/mtk_drm_drv.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/mediatek/mtk_drm_drv.c b/drivers/gpu/drm/mediatek/mtk_drm_drv.c
index 2d6a979afe8f9..cdd506c803733 100644
--- a/drivers/gpu/drm/mediatek/mtk_drm_drv.c
+++ b/drivers/gpu/drm/mediatek/mtk_drm_drv.c
@@ -421,6 +421,7 @@ static int mtk_drm_kms_init(struct drm_device *drm)
struct mtk_drm_private *private = drm->dev_private;
struct mtk_drm_private *priv_n;
struct device *dma_dev = NULL;
+ struct drm_crtc *crtc;
int ret, i, j;
if (drm_firmware_drivers_only())
@@ -495,7 +496,9 @@ static int mtk_drm_kms_init(struct drm_device *drm)
}
/* Use OVL device for all DMA memory allocations */
- dma_dev = mtk_drm_crtc_dma_dev_get(drm_crtc_from_index(drm, 0));
+ crtc = drm_crtc_from_index(drm, 0);
+ if (crtc)
+ dma_dev = mtk_drm_crtc_dma_dev_get(crtc);
if (!dma_dev) {
ret = -ENODEV;
dev_err(drm->dev, "Need at least one OVL device\n");
--
2.43.0
