RE: [PATCH v2 3/5] ASoC: rt5640: Fix sleep in atomic context

[David Laight <David.Laight@ACULAB.COM>]

From: Sameer Pujar
> Sent: 29 June 2023 06:12
> 
> Following prints are observed while testing audio on Jetson AGX Orin which
> has onboard RT5640 audio codec:
> 
>   BUG: sleeping function called from invalid context at kernel/workqueue.c:3027
>   in_atomic(): 1, irqs_disabled(): 128, non_block: 0, pid: 0, name: swapper/0
>   preempt_count: 10001, expected: 0
>   RCU nest depth: 0, expected: 0
>   ------------[ cut here ]------------
>   WARNING: CPU: 0 PID: 0 at kernel/irq/handle.c:159 __handle_irq_event_percpu+0x1e0/0x270
>   ---[ end trace ad1c64905aac14a6 ]-
> 
> The IRQ handler rt5640_irq() runs in interrupt context and can sleep
> during cancel_delayed_work_sync().
> 
> Fix this by running IRQ handler, rt5640_irq(), in thread context.
> Hence replace request_irq() calls with devm_request_threaded_irq().

My 'gut feel' is that this will just move the problem elsewhere.

If the ISR is responsible for adding audio buffers (etc) then it is
also not unlikely that the scheduling delays in running a threaded ISR
will cause audio glitches if the system is busy.

> 
> Fixes: 051dade34695 ("ASoC: rt5640: Fix the wrong state of JD1 and JD2")
> Cc: stable@vger.kernel.org
> Cc: Oder Chiou <oder_chiou@realtek.com>
> Signed-off-by: Sameer Pujar <spujar@nvidia.com>
> ---
>  sound/soc/codecs/rt5640.c | 12 +++++++-----
>  1 file changed, 7 insertions(+), 5 deletions(-)
> 
> diff --git a/sound/soc/codecs/rt5640.c b/sound/soc/codecs/rt5640.c
> index 0ed4fa2..e24ed75 100644
> --- a/sound/soc/codecs/rt5640.c
> +++ b/sound/soc/codecs/rt5640.c
> @@ -2567,9 +2567,10 @@ static void rt5640_enable_jack_detect(struct snd_soc_component *component,
>  	if (jack_data && jack_data->use_platform_clock)
>  		rt5640->use_platform_clock = jack_data->use_platform_clock;
> 
> -	ret = request_irq(rt5640->irq, rt5640_irq,
> -			  IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
> -			  "rt5640", rt5640);
> +	ret = devm_request_threaded_irq(component->dev, rt5640->irq,
> +					NULL, rt5640_irq,
> +					IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
> +					"rt5640", rt5640);

You need a comment saying this must be a threaded IRQ because the ISR
calls cancel_delayed_work_sync().

	David

>  	if (ret) {
>  		dev_warn(component->dev, "Failed to reguest IRQ %d: %d\n", rt5640->irq, ret);
>  		rt5640_disable_jack_detect(component);
> @@ -2622,8 +2623,9 @@ static void rt5640_enable_hda_jack_detect(
> 
>  	rt5640->jack = jack;
> 
> -	ret = request_irq(rt5640->irq, rt5640_irq,
> -			  IRQF_TRIGGER_RISING | IRQF_ONESHOT, "rt5640", rt5640);
> +	ret = devm_request_threaded_irq(component->dev, rt5640->irq,
> +					NULL, rt5640_irq, IRQF_TRIGGER_RISING | IRQF_ONESHOT,
> +					"rt5640", rt5640);
>  	if (ret) {
>  		dev_warn(component->dev, "Failed to reguest IRQ %d: %d\n", rt5640->irq, ret);
>  		rt5640->irq = -ENXIO;
> --
> 2.7.4

-
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