RE: [EXT] Re: [PATCH v1 2/5] drm: bridge: dw_hdmi: enable overflow workaround for v2.13a

[Sandor Yu]

Hi,

> -----Original Message-----
> From: Neil Armstrong <narmstrong@xxxxxxxxxxxx>
> Sent: 2022年4月6日 17:17
> To: Sandor Yu <sandor.yu@xxxxxxx>; dri-devel@xxxxxxxxxxxxxxxxxxxxx;
> linux-kernel@xxxxxxxxxxxxxxx; andrzej.hajda@xxxxxxxxx;
> robert.foss@xxxxxxxxxx; Laurent.pinchart@xxxxxxxxxxxxxxxx;
> jonas@xxxxxxxxx; jernej.skrabec@xxxxxxxxx
> Cc: S.J. Wang <shengjiu.wang@xxxxxxx>; cai.huoqing@xxxxxxxxx;
> maxime@xxxxxxxxxx; harry.wentland@xxxxxxx; hverkuil-cisco@xxxxxxxxx;
> amuel@xxxxxxxxxxxx
> Subject: [EXT] Re: [PATCH v1 2/5] drm: bridge: dw_hdmi: enable overflow
> workaround for v2.13a
> 
> Caution: EXT Email
> 
> Hi,
> 
> On 06/04/2022 10:48, Sandor.yu@xxxxxxx wrote:
> > From: Sandor Yu <Sandor.yu@xxxxxxx>
> >
> > iMX865 HDMI (v2.13a) have been identified as needing the workaround.
> > Tests show that one iteration is enough.
> >
> > Without the workaround, iMX865 HDMI audio may not work after cable
> > plugout/in, because HDMI mode is not really set in register
> > HDMI_FC_INVIDCONF.
> >
> > Signed-off-by: Sandor Yu <Sandor.yu@xxxxxxx>
> > ---
> >   drivers/gpu/drm/bridge/synopsys/dw-hdmi.c | 7 ++++---
> >   1 file changed, 4 insertions(+), 3 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c
> > b/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c
> > index 4befc104d220..b11577de4836 100644
> > --- a/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c
> > +++ b/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c
> > @@ -2087,9 +2087,9 @@ static void dw_hdmi_clear_overflow(struct
> dw_hdmi *hdmi)
> >        *
> >        * The number of iterations matters and depends on the HDMI TX
> revision
> >        * (and possibly on the platform). So far i.MX6Q (v1.30a), i.MX6DL
> > -      * (v1.31a) and multiple Allwinner SoCs (v1.32a) have been
> identified
> > -      * as needing the workaround, with 4 iterations for v1.30a and 1
> > -      * iteration for others.
> > +      * (v1.31a), iMX865(v2.13a) and multiple Allwinner SoCs (v1.32a)
> > +      * have been identified as needing the workaround,
> > +      * with 4 iterations for v1.30a and 1 iteration for others.
> >        * The Amlogic Meson GX SoCs (v2.01a) have been identified as
> needing
> >        * the workaround with a single iteration.
> >        * The Rockchip RK3288 SoC (v2.00a) and RK3328/RK3399 SoCs
> > (v2.11a) have @@ -2106,6 +2106,7 @@ static void
> dw_hdmi_clear_overflow(struct dw_hdmi *hdmi)
> >       case 0x201a:
> >       case 0x211a:
> >       case 0x212a:
> > +     case 0x213a:
> >               count = 1;
> >               break;
> 
> At some point we must consider only v1.30a needs 4, and other needs 1.
> 
> It would be simpler to put the "count = 1" in a default case.
> 
Agree, I will put the "count = 1 " to default case.
> The comment change is still welcome so we can track.
> 
> Thanks,
> Neil
> 
> >       default:

Thanks
Sandor