Re: [PATCH] drm/bridge: adv7511: fix crash on irq during probe

[Laurent Pinchart <laurent.pinchart@ideasonboard.com>]

Hello Alvin,

On Sat, Oct 14, 2023 at 08:46:12PM +0200, Alvin Šipraga wrote:
> From: Mads Bligaard Nielsen <bli@bang-olufsen.dk>
> 
> Moved IRQ registration down to end of adv7511_probe().
> 
> If an IRQ already is pending during adv7511_probe
> (before adv7511_cec_init) then cec_received_msg_ts
> could crash using uninitialized data:
> 
>     Unable to handle kernel read from unreadable memory at virtual address 00000000000003d5
>     Internal error: Oops: 96000004 [#1] PREEMPT_RT SMP
>     Call trace:
>      cec_received_msg_ts+0x48/0x990 [cec]
>      adv7511_cec_irq_process+0x1cc/0x308 [adv7511]
>      adv7511_irq_process+0xd8/0x120 [adv7511]
>      adv7511_irq_handler+0x1c/0x30 [adv7511]
>      irq_thread_fn+0x30/0xa0
>      irq_thread+0x14c/0x238
>      kthread+0x190/0x1a8
> 
> Fixes: 3b1b975003e4 ("drm: adv7511/33: add HDMI CEC support")

Isn't the issue older than that ?

> Signed-off-by: Mads Bligaard Nielsen <bli@bang-olufsen.dk>
> Signed-off-by: Alvin Šipraga <alsi@bang-olufsen.dk>

With the Fixes: tag updated,

Reviewed-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>

> ---
>  drivers/gpu/drm/bridge/adv7511/adv7511_drv.c | 22 +++++++++++-----------
>  1 file changed, 11 insertions(+), 11 deletions(-)
> 
> diff --git a/drivers/gpu/drm/bridge/adv7511/adv7511_drv.c b/drivers/gpu/drm/bridge/adv7511/adv7511_drv.c
> index d518de88b5c3..71022cb8abe4 100644
> --- a/drivers/gpu/drm/bridge/adv7511/adv7511_drv.c
> +++ b/drivers/gpu/drm/bridge/adv7511/adv7511_drv.c
> @@ -1291,17 +1291,6 @@ static int adv7511_probe(struct i2c_client *i2c)
>  
>  	INIT_WORK(&adv7511->hpd_work, adv7511_hpd_work);
>  
> -	if (i2c->irq) {
> -		init_waitqueue_head(&adv7511->wq);
> -
> -		ret = devm_request_threaded_irq(dev, i2c->irq, NULL,
> -						adv7511_irq_handler,
> -						IRQF_ONESHOT, dev_name(dev),
> -						adv7511);
> -		if (ret)
> -			goto err_unregister_cec;
> -	}
> -
>  	adv7511_power_off(adv7511);
>  
>  	i2c_set_clientdata(i2c, adv7511);
> @@ -1325,6 +1314,17 @@ static int adv7511_probe(struct i2c_client *i2c)
>  
>  	adv7511_audio_init(dev, adv7511);
>  
> +	if (i2c->irq) {
> +		init_waitqueue_head(&adv7511->wq);
> +
> +		ret = devm_request_threaded_irq(dev, i2c->irq, NULL,
> +						adv7511_irq_handler,
> +						IRQF_ONESHOT, dev_name(dev),
> +						adv7511);
> +		if (ret)
> +			goto err_unregister_audio;
> +	}
> +
>  	if (adv7511->type == ADV7533 || adv7511->type == ADV7535) {
>  		ret = adv7533_attach_dsi(adv7511);
>  		if (ret)
> 

-- 
Regards,

Laurent Pinchart