Hi, Michael: Michael Walle <mwalle@xxxxxxxxxx> 於 2023年9月5日 週二 下午4:49寫道： > > 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. Applied to mediatek-drm-fixes [1], thanks. [1] https://git.kernel.org/pub/scm/linux/kernel/git/chunkuang.hu/linux.git/log/?h=mediatek-drm-fixes Regards, Chun-Kuang. > > 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> > --- > v4: > - collected tags > v3: > - none > 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 >
