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>
---
v2:
- collected tags
- fixed typos
---
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 93552d76b6e7..2c582498817e 100644
--- a/drivers/gpu/drm/mediatek/mtk_drm_drv.c
+++ b/drivers/gpu/drm/mediatek/mtk_drm_drv.c
@@ -420,6 +420,7 @@ 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())
@@ -494,7 +495,9 @@ 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");
--
2.39.2
