Hi, Dan:
On Thu, 2024-09-12 at 11:44 +0300, Dan Carpenter wrote:
>
> External email : Please do not click links or open attachments until you have verified the sender or the content.
> In mtk_crtc_create(), if the call to mbox_request_channel() fails then we
> set the "mtk_crtc->cmdq_client.chan" pointer to NULL. In that situation,
> we do not call cmdq_pkt_create().
>
> During the cleanup, we need to check if the "mtk_crtc->cmdq_client.chan"
> is NULL first before calling cmdq_pkt_destroy(). Calling
> cmdq_pkt_destroy() is unnecessary if we didn't call cmdq_pkt_create() and
> it will result in a NULL pointer dereference.
Reviewed-by: CK Hu <ck.hu@xxxxxxxxxxxx>
>
> Fixes: 7627122fd1c0 ("drm/mediatek: Add cmdq_handle in mtk_crtc")
> Signed-off-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
> ---
> drivers/gpu/drm/mediatek/mtk_crtc.c | 3 +--
> 1 file changed, 1 insertion(+), 2 deletions(-)
>
> diff --git a/drivers/gpu/drm/mediatek/mtk_crtc.c b/drivers/gpu/drm/mediatek/mtk_crtc.c
> index 175b00e5a253..c15013792583 100644
> --- a/drivers/gpu/drm/mediatek/mtk_crtc.c
> +++ b/drivers/gpu/drm/mediatek/mtk_crtc.c
> @@ -127,9 +127,8 @@ static void mtk_crtc_destroy(struct drm_crtc *crtc)
>
> mtk_mutex_put(mtk_crtc->mutex);
> #if IS_REACHABLE(CONFIG_MTK_CMDQ)
> -cmdq_pkt_destroy(&mtk_crtc->cmdq_client, &mtk_crtc->cmdq_handle);
> -
> if (mtk_crtc->cmdq_client.chan) {
> +cmdq_pkt_destroy(&mtk_crtc->cmdq_client, &mtk_crtc->cmdq_handle);
> mbox_free_channel(mtk_crtc->cmdq_client.chan);
> mtk_crtc->cmdq_client.chan = NULL;
> }
> --
> 2.45.2
>
>
