linux-kernel - Re: [PATCH v4, 4/4] drm/mediatek: Add pull-down MIPI operation in mtk_dsi

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Message-ID: <720c5ede369357fb40152588c441614456b0f96f.camel@mediatek.com>
Date:   Wed, 13 Apr 2022 17:04:40 +0800
From:   CK Hu <ck.hu@...iatek.com>
To:     <xinlei.lee@...iatek.com>, <chunkuang.hu@...nel.org>,
        <p.zabel@...gutronix.de>, <airlied@...ux.ie>, <daniel@...ll.ch>,
        <matthias.bgg@...il.com>, <rex-bc.chen@...iatek.com>
CC:     <jitao.shi@...iatek.com>, <linux-kernel@...r.kernel.org>,
        <dri-devel@...ts.freedesktop.org>,
        <Project_Global_Chrome_Upstream_Group@...iatek.com>,
        <linux-mediatek@...ts.infradead.org>,
        <linux-arm-kernel@...ts.infradead.org>
Subject: Re: [PATCH v4, 4/4] drm/mediatek: Add pull-down MIPI operation in
 mtk_dsi_poweroff function

Hi, Xinlei:

On Mon, 2022-04-11 at 10:31 +0800, xinlei.lee@...iatek.com wrote:
> From: Xinlei Lee <xinlei.lee@...iatek.com>
> 
> In the dsi_enable function, mtk_dsi_rxtx_control is to
> pull up the MIPI signal operation. Before dsi_disable,
> MIPI should also be pulled down by writing a register 
> instead of disabling dsi.
> 
> If disable dsi without pulling the mipi signal low, the value of
> the register will still maintain the setting of the mipi signal being
> pulled high.
> After resume, even if the mipi signal is not pulled high, it will
> still
> be in the high state.

After add Fixes tag for [1], then

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

[1] 
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/drivers/gpu/drm/mediatek/mtk_dsi.c?h=v5.18-rc2&id=2e54c14e310f655bb0915413e8e4a3da67c78a66

> 
> Signed-off-by: Jitao Shi <jitao.shi@...iatek.com>
> Signed-off-by: Xinlei Lee <xinlei.lee@...iatek.com>
> ---
>  drivers/gpu/drm/mediatek/mtk_dsi.c | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/drivers/gpu/drm/mediatek/mtk_dsi.c
> b/drivers/gpu/drm/mediatek/mtk_dsi.c
> index 9ad6f08c8bfe..e35343357f90 100644
> --- a/drivers/gpu/drm/mediatek/mtk_dsi.c
> +++ b/drivers/gpu/drm/mediatek/mtk_dsi.c
> @@ -676,6 +676,8 @@ static void mtk_dsi_poweroff(struct mtk_dsi *dsi)
>  	mtk_dsi_reset_engine(dsi);
>  	mtk_dsi_lane0_ulp_mode_enter(dsi);
>  	mtk_dsi_clk_ulp_mode_enter(dsi);
> +	/* set the lane number as 0 to pull down mipi */
> +	writel(0, dsi->regs + DSI_TXRX_CTRL);
>  
>  	mtk_dsi_disable(dsi);
>