[PATCH] drm/mediatek: Fix config_updating flag never false when no mbox channel

[Chun-Kuang Hu]

Hi, Jason:

Jason-JH Lin <jason-jh.lin at mediatek.com> 於 2025年2月24日 週一 下午1:13寫道：
>
> When CONFIG_MTK_CMDQ is enabled, if the display is controlled by the CPU
> while other hardware is controlled by the GCE, the display will encounter
> a mbox request channel failure.
> However, it will still enter the CONFIG_MTK_CMDQ statement, causing the
> config_updating flag to never be set to false. As a result, no page flip
> event is sent back to user space, and the screen does not update.

Applied to mediatek-drm-next [1], thanks.

[1] https://web.git.kernel.org/pub/scm/linux/kernel/git/chunkuang.hu/linux.git/log/?h=mediatek-drm-next

Regards,
Chun-Kuang.

>
> Fixes: da03801ad08f ("drm/mediatek: Move mtk_crtc_finish_page_flip() to ddp_cmdq_cb()")
> Signed-off-by: Jason-JH Lin <jason-jh.lin at mediatek.com>
> ---
>  drivers/gpu/drm/mediatek/mtk_crtc.c | 5 +++--
>  1 file changed, 3 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/gpu/drm/mediatek/mtk_crtc.c b/drivers/gpu/drm/mediatek/mtk_crtc.c
> index 5674f5707cca..cfc4867296b8 100644
> --- a/drivers/gpu/drm/mediatek/mtk_crtc.c
> +++ b/drivers/gpu/drm/mediatek/mtk_crtc.c
> @@ -620,13 +620,14 @@ static void mtk_crtc_update_config(struct mtk_crtc *mtk_crtc, bool needs_vblank)
>
>                 mbox_send_message(mtk_crtc->cmdq_client.chan, cmdq_handle);
>                 mbox_client_txdone(mtk_crtc->cmdq_client.chan, 0);
> +               goto update_config_out;
>         }
> -#else
> +#endif
>         spin_lock_irqsave(&mtk_crtc->config_lock, flags);
>         mtk_crtc->config_updating = false;
>         spin_unlock_irqrestore(&mtk_crtc->config_lock, flags);
> -#endif
>
> +update_config_out:
>         mutex_unlock(&mtk_crtc->hw_lock);
>  }
>
> --
> 2.43.0
>