Re: [PATCH 2/3] drm/mediatek: make sure previous message done or be aborted before send

[CK Hu]

Hi, Bibby:

On Fri, 2020-02-14 at 12:49 +0800, Bibby Hsieh wrote:
> Mediatek CMDQ driver removed atomic parameter and implementation
> related to atomic. DRM driver need to make sure previous message
> done or be aborted before we send next message.
> 
> If previous message is still waiting for event, it means the
> setting hasn't been updated into display hardware register,
> we can abort the message and send next message to update the
> newest setting into display hardware.
> If previous message already started, we have to wait it until
> transmission has been completed.
> 
> So we flush mbox client before we send new message to controller
> driver.
> 

Reviewed-by: CK Hu <ck.hu@xxxxxxxxxxxx>

> This patch depends on ptach:
> [0/3] Remove atomic_exec
> https://patchwork.kernel.org/cover/11381677/
> 
> Signed-off-by: Bibby Hsieh <bibby.hsieh@xxxxxxxxxxxx>
> ---
>  drivers/gpu/drm/mediatek/mtk_drm_crtc.c | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/drivers/gpu/drm/mediatek/mtk_drm_crtc.c b/drivers/gpu/drm/mediatek/mtk_drm_crtc.c
> index 3c53ea22208c..e35b66c5ba0f 100644
> --- a/drivers/gpu/drm/mediatek/mtk_drm_crtc.c
> +++ b/drivers/gpu/drm/mediatek/mtk_drm_crtc.c
> @@ -491,6 +491,7 @@ static void mtk_drm_crtc_hw_config(struct mtk_drm_crtc *mtk_crtc)
>  	}
>  #if IS_ENABLED(CONFIG_MTK_CMDQ)
>  	if (mtk_crtc->cmdq_client) {
> +		mbox_flush(mtk_crtc->cmdq_client->chan, 2000);
>  		cmdq_handle = cmdq_pkt_create(mtk_crtc->cmdq_client, PAGE_SIZE);
>  		cmdq_pkt_clear_event(cmdq_handle, mtk_crtc->cmdq_event);
>  		cmdq_pkt_wfe(cmdq_handle, mtk_crtc->cmdq_event);