Re: [PATCH] soc: mmsys: mediatek: add mask to mmsys routes

From: Hsin-Yi Wang
Date: Wed Jul 28 2021 - 23:15:53 EST


On Wed, Jul 28, 2021 at 1:41 AM Frank Wunderlich <linux@xxxxxxxxx> wrote:
>
> From: CK Hu <ck.hu@xxxxxxxxxxxx>
>
> SOUT has many bits and need to be cleared before set new value.
> Write only could do the clear, but for MOUT, it clears bits that
> should not be cleared. So use a mask to reset only the needed bits.
>
> this fixes HDMI issues on MT7623/BPI-R2 since 5.13
>
> Cc: stable@xxxxxxxxxxxxxxx
> Fixes: 440147639ac7 ("soc: mediatek: mmsys: Use an array for setting the routing registers")
> Signed-off-by: Frank Wunderlich <frank-w@xxxxxxxxxxxxxxx>
> Signed-off-by: CK Hu <ck.hu@xxxxxxxxxxxx>
> ---
> code is taken from here (upstreamed without mask part)
> https://chromium-review.googlesource.com/c/chromiumos/third_party/kernel/+/2345186/5
> basicly CK Hu's code so i set him as author
> ---
> drivers/soc/mediatek/mtk-mmsys.c | 7 +-
> drivers/soc/mediatek/mtk-mmsys.h | 133 +++++++++++++++++++++----------
> 2 files changed, 98 insertions(+), 42 deletions(-)
>
> diff --git a/drivers/soc/mediatek/mtk-mmsys.c b/drivers/soc/mediatek/mtk-mmsys.c
> index 080660ef11bf..0f949896fd06 100644
> --- a/drivers/soc/mediatek/mtk-mmsys.c
> +++ b/drivers/soc/mediatek/mtk-mmsys.c
> @@ -68,7 +68,9 @@ void mtk_mmsys_ddp_connect(struct device *dev,
>
> for (i = 0; i < mmsys->data->num_routes; i++)
> if (cur == routes[i].from_comp && next == routes[i].to_comp) {
> - reg = readl_relaxed(mmsys->regs + routes[i].addr) | routes[i].val;
> + reg = readl_relaxed(mmsys->regs + routes[i].addr);
> + reg &= ~routes[i].mask;
> + reg |= routes[i].val;
> writel_relaxed(reg, mmsys->regs + routes[i].addr);
> }
> }
> @@ -85,7 +87,8 @@ void mtk_mmsys_ddp_disconnect(struct device *dev,
>
> for (i = 0; i < mmsys->data->num_routes; i++)
> if (cur == routes[i].from_comp && next == routes[i].to_comp) {
> - reg = readl_relaxed(mmsys->regs + routes[i].addr) & ~routes[i].val;
> + reg = readl_relaxed(mmsys->regs + routes[i].addr);
> + reg &= ~routes[i].mask;

This patch is breaking the mt8183 internal display. I think it's
because ~routes[i].val; is removed?
Also what should the routes[i].mask be if it's not set in
mmsys_mt8183_routing_table?

> writel_relaxed(reg, mmsys->regs + routes[i].addr);
> }
> }
<snip>