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References: <20210923090232.61559-1-yipeng.chen@amd.com>
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From:   Alex Deucher <alexdeucher@gmail.com>
Date:   Thu, 23 Sep 2021 08:56:27 -0400
Message-ID: <CADnq5_Put1U-X8MBS4Gpxo2zkkyNCS6yum+X3q+H-30xNn31_A@mail.gmail.com>
Subject: Re: [PATCH] drm/amd/display: Fix randomly flicking on overlay with
 enabled ABM
To:     yipeng.chen@amd.com
Cc:     "Wentland, Harry" <harry.wentland@amd.com>,
        "Leo (Sunpeng) Li" <sunpeng.li@amd.com>,
        "Deucher, Alexander" <alexander.deucher@amd.com>,
        Christian Koenig <christian.koenig@amd.com>,
        Dave Airlie <airlied@linux.ie>,
        Daniel Vetter <daniel@ffwll.ch>,
        Qingqing Zhuo <qingqing.zhuo@amd.com>,
        "Cyr, Aric" <Aric.Cyr@amd.com>, Anson Jacob <Anson.Jacob@amd.com>,
        Bindu Ramamurthy <bindu.r@amd.com>,
        Martin Tsai <martin.tsai@amd.com>, bing.guo@amd.com,
        roy.chan@amd.com, George Shen <george.shen@amd.com>,
        Joshua Aberback <joshua.aberback@amd.com>,
        Ashley Thomas <Ashley.Thomas2@amd.com>, Jing.Zhou@amd.com,
        dale.zhao@amd.com, amd-gfx list <amd-gfx@lists.freedesktop.org>,
        Maling list - DRI developers 
        <dri-devel@lists.freedesktop.org>,
        LKML <linux-kernel@vger.kernel.org>, Roman Li <Roman.Li@amd.com>
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On Thu, Sep 23, 2021 at 5:03 AM <yipeng.chen@amd.com> wrote:
>
> From: "Yipeng Chen (Jasber)" <yipeng.chen@amd.com>
>
> [Why]
> Enabled ABM (level != 0) would raise short pluse irq DC_IRQ_SOURCE_HPD1RX
> randomly with PSR error LINK_CRC_ERROR. Actually there is no hot plugging
> on EDP panel. After correcting CRC error, there is no need to send drm
> hotplug event.
>
> [How]
> Returning false would skip doing hot-plug when handle_hpd_irq_psr_sink()
> handled irq. Hot-plug process causes visible flicking on overlay.
>
> Signed-off-by: Yipeng Chen (Jasber) <yipeng.chen@amd.com>
> Reviewed-by: Roman Li <Roman.Li@amd.com>
>              Anthony Koo <Anthony.Koo@amd.com>

Each reviewer should be called out on a separate line E.g.,
Reviewed-by: Roman Li <Roman.Li@amd.com>
Reviewed-by: Anthony Koo <Anthony.Koo@amd.com>


> ---
>  drivers/gpu/drm/amd/display/dc/core/dc_link_dp.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/amd/display/dc/core/dc_link_dp.c b/drivers/gpu/drm/amd/display/dc/core/dc_link_dp.c
> index 1e4794e2825c..9b9fbe5e9bd4 100644
> --- a/drivers/gpu/drm/amd/display/dc/core/dc_link_dp.c
> +++ b/drivers/gpu/drm/amd/display/dc/core/dc_link_dp.c
> @@ -3007,7 +3007,7 @@ bool dc_link_handle_hpd_rx_irq(struct dc_link *link, union hpd_irq_data *out_hpd
>
>         if (handle_hpd_irq_psr_sink(link))
>                 /* PSR-related error was detected and handled */
> -               return true;
> +               return false;
>
>         /* If PSR-related error handled, Main link may be off,
>          * so do not handle as a normal sink status change interrupt.
> --
> 2.25.1
>