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Message-ID: <0ae84b3c-9935-4cb5-9ed5-3fc87a416857@linux.dev>
Date: Thu, 16 May 2024 19:07:43 +0800
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Subject: Re: [PATCH] drm/bridge: adv7511: Exit interrupt handling when
 necessary
To: Liu Ying <victor.liu@nxp.com>, dri-devel@lists.freedesktop.org,
 linux-kernel@vger.kernel.org
Cc: andrzej.hajda@intel.com, neil.armstrong@linaro.org, rfoss@kernel.org,
 Laurent.pinchart@ideasonboard.com, jonas@kwiboo.se,
 jernej.skrabec@gmail.com, maarten.lankhorst@linux.intel.com,
 mripard@kernel.org, tzimmermann@suse.de, airlied@gmail.com, daniel@ffwll.ch,
 biju.das.jz@bp.renesas.com, dmitry.baryshkov@linaro.org,
 u.kleine-koenig@pengutronix.de, aford173@gmail.com, jani.nikula@intel.com,
 bli@bang-olufsen.dk
References: <20240516101006.2388767-1-victor.liu@nxp.com>
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From: Sui Jingfeng <sui.jingfeng@linux.dev>
In-Reply-To: <20240516101006.2388767-1-victor.liu@nxp.com>
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Hi,


On 5/16/24 18:10, Liu Ying 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.
> 
> 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>
> ---
>   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/drm/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 *adv7511, 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 &&

Maybe you could use 'if (process_hpd)' here.

> +	    !(irq0 & (ADV7511_INT0_HPD | ADV7511_INT0_EDID_READY)) &&
>   	    !(irq1 & ADV7511_INT1_DDC_ERROR))
>   		return -ENODATA;
>   

-- 
Best regards
Sui