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From: Adam Ford <aford173@gmail.com>
Date: Thu, 16 May 2024 07:22:38 -0500
Message-ID: <CAHCN7xKiVYPfvu1h0Nz2sRCt=P2zfdS1aMdU=LAeptNv0JbfJw@mail.gmail.com>
Subject: Re: [PATCH] drm/bridge: adv7511: Exit interrupt handling when necessary
To: Liu Ying <victor.liu@nxp.com>
Cc: dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org, 
	andrzej.hajda@intel.com, neil.armstrong@linaro.org, rfoss@kernel.org, 
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	airlied@gmail.com, daniel@ffwll.ch, biju.das.jz@bp.renesas.com, 
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On Thu, May 16, 2024 at 5:01=E2=80=AFAM Liu Ying <victor.liu@nxp.com> wrote=
:
>
> Commit f3d9683346d6 ("drm/bridge: adv7511: Allow IRQ to share GPIO pins")
> fails to consider the case where adv7511->i2c_main->irq is zero, i.e.,
> no interrupt requested at all.

Sorry about that.

>
> Without interrupt, adv7511_wait_for_edid() could return -EIO sometimes,
> because it polls adv7511->edid_read flag by calling adv7511_irq_process()
> a few times, but adv7511_irq_process() happens to refuse to handle
> interrupt by returning -ENODATA.  Hence, EDID retrieval fails randomly.
>
> Fix the issue by checking adv7511->i2c_main->irq before exiting interrupt
> handling from adv7511_irq_process().
>
> Fixes: f3d9683346d6 ("drm/bridge: adv7511: Allow IRQ to share GPIO pins")
> Signed-off-by: Liu Ying <victor.liu@nxp.com>

Acked-by:  Adam Ford <aford173@gmail.com>

> ---
>  drivers/gpu/drm/bridge/adv7511/adv7511_drv.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/bridge/adv7511/adv7511_drv.c b/drivers/gpu/d=
rm/bridge/adv7511/adv7511_drv.c
> index 6089b0bb9321..2074fa3c1b7b 100644
> --- a/drivers/gpu/drm/bridge/adv7511/adv7511_drv.c
> +++ b/drivers/gpu/drm/bridge/adv7511/adv7511_drv.c
> @@ -479,7 +479,8 @@ static int adv7511_irq_process(struct adv7511 *adv751=
1, bool process_hpd)
>                 return ret;
>
>         /* If there is no IRQ to handle, exit indicating no IRQ data */
> -       if (!(irq0 & (ADV7511_INT0_HPD | ADV7511_INT0_EDID_READY)) &&
> +       if (adv7511->i2c_main->irq &&
> +           !(irq0 & (ADV7511_INT0_HPD | ADV7511_INT0_EDID_READY)) &&
>             !(irq1 & ADV7511_INT1_DDC_ERROR))
>                 return -ENODATA;
>
> --
> 2.37.1
>