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

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Date:   Tue, 18 Feb 2020 16:22:42 +0800
From:   CK Hu <ck.hu@...iatek.com>
To:     Bibby Hsieh <bibby.hsieh@...iatek.com>
CC:     David Airlie <airlied@...ux.ie>,
        Matthias Brugger <matthias.bgg@...il.com>,
        Daniel Vetter <daniel.vetter@...ll.ch>,
        <dri-devel@...ts.freedesktop.org>,
        <linux-mediatek@...ts.infradead.org>,
        Philipp Zabel <p.zabel@...gutronix.de>,
        YT Shen <yt.shen@...iatek.com>,
        Thierry Reding <thierry.reding@...il.com>,
        <linux-arm-kernel@...ts.infradead.org>, <tfiga@...omium.org>,
        <drinkcat@...omium.org>, <linux-kernel@...r.kernel.org>,
        <srv_heupstream@...iatek.com>
Subject: Re: [PATCH 2/3] drm/mediatek: make sure previous message done or be
 aborted before send

Hi, Bibby:

On Fri, 2020-02-14 at 14:48 +0800, CK Hu wrote:
> 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@...iatek.com>
> 
> > This patch depends on ptach:
> > [0/3] Remove atomic_exec
> > https://patchwork.kernel.org/cover/11381677/
> > 

This patch does not depend on any patch, so applied to
mediatek-drm-fixes-5.6 [1], thanks.

[1]
https://github.com/ckhu-mediatek/linux.git-tags/commits/mediatek-drm-fixes-5.6

Regards,
CK

> > Signed-off-by: Bibby Hsieh <bibby.hsieh@...iatek.com>
> > ---
> >  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);
>