Re: [PATCH] soc: mediatek: mt8192-mmsys: Fix dither to dsi0 path's input sel

From: Alyssa Rosenzweig
Date: Mon Feb 14 2022 - 09:36:38 EST


> In commit d687e056a18f ("soc: mediatek: mmsys: Add mt8192 mmsys routing table"),
> the mmsys routing table for mt8192 was introduced but the input selector
> for DITHER->DSI0 has no value assigned to it.
>
> This means that we are clearing bit 0 instead of setting it, blocking
> communication between these two blocks; due to that, any display that
> is connected to DSI0 will not work, as no data will go through.
> The effect of that issue is that, during bootup, the DRM will block for
> some time, while atomically waiting for a vblank that never happens;
> later, the situation doesn't get better, leaving the display in a
> non-functional state.
>
> To fix this issue, fix the route entry in the table by assigning the
> dither input selector to MT8192_DISP_DSI0_SEL_IN.
>
> Fixes: d687e056a18f ("soc: mediatek: mmsys: Add mt8192 mmsys routing table")
> Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@xxxxxxxxxxxxx>
> ---
> drivers/soc/mediatek/mt8192-mmsys.h | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/soc/mediatek/mt8192-mmsys.h b/drivers/soc/mediatek/mt8192-mmsys.h
> index 6f0a57044a7b..6aae0b12b6ff 100644
> --- a/drivers/soc/mediatek/mt8192-mmsys.h
> +++ b/drivers/soc/mediatek/mt8192-mmsys.h
> @@ -53,7 +53,8 @@ static const struct mtk_mmsys_routes mmsys_mt8192_routing_table[] = {
> MT8192_AAL0_SEL_IN_CCORR0
> }, {
> DDP_COMPONENT_DITHER, DDP_COMPONENT_DSI0,
> - MT8192_DISP_DSI0_SEL_IN, MT8192_DSI0_SEL_IN_DITHER0
> + MT8192_DISP_DSI0_SEL_IN, MT8192_DSI0_SEL_IN_DITHER0,
> + MT8192_DSI0_SEL_IN_DITHER0
> }, {
> DDP_COMPONENT_RDMA0, DDP_COMPONENT_COLOR0,
> MT8192_DISP_RDMA0_SOUT_SEL, MT8192_RDMA0_SOUT_COLOR0,

Tested-by: Alyssa Rosenzweig <alyssa.rosenzweig@xxxxxxxxxxxxx>