Re: [PATCH v7 18/34] pinctrl: airoha: remove not needed irq_type[] array

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:

Pre-existing issues:
- [High] The irq_chip callbacks (mask, unmask, ack) call regmap functions on a regmap that uses a sleepable spinlock, leading to a sleeping in atomic bug on PREEMPT_RT.
--

--- Patch [18]: [PATCH v7 18/34] pinctrl: airoha: remove not needed irq_type[] array ---
commit 36bbed24ea5a5464c148e69474b3311bae84ccc0
Author: Mikhail Kshevetskiy <mikhail.kshevetskiy@iopsys.eu>

pinctrl: airoha: remove not needed irq_type[] array

irq_type[] array inside airoha_pinctrl_gpiochip structure is not
actually necessary. Use trigger type from 'struct irq_data' instead.

> diff --git a/drivers/pinctrl/airoha/pinctrl-airoha.c b/drivers/pinctrl/airoha/pinctrl-airoha.c
> index 0a865cf0c2728..6d4b282c21eaf 100644
> --- a/drivers/pinctrl/airoha/pinctrl-airoha.c
> +++ b/drivers/pinctrl/airoha/pinctrl-airoha.c

[ ... ]

> @@ -2613,7 +2611,7 @@ static void airoha_irq_mask(struct irq_data *data)
>  	u8 index = data->hwirq / AIROHA_REG_GPIOCTRL_NUM_PIN;
>  	u32 mask = GENMASK(2 * offset + 1, 2 * offset);
>  
> -	if (data->hwirq >= ARRAY_SIZE(gpiochip->irq_type))
> +	if (data->hwirq >= AIROHA_NUM_PINS)
>  		return;
>  
>  	regmap_clear_bits(pinctrl->regmap, gpiochip->level[index], mask);

[Severity: High]
This is a pre-existing issue and was not introduced by the patch under review,
but could these regmap operations trigger a sleeping in atomic bug on preempt-rt
kernels?

The genirq core calls irq_chip callbacks such as airoha_irq_mask(),
airoha_irq_unmask(), and airoha_irq_ack() while holding the irq descriptor lock.
This lock is a raw_spinlock_t which disables interrupts and preemption.

Because pinctrl->regmap is instantiated from a syscon without setting
use_raw_spinlock = true, its internal lock defaults to a standard spinlock_t.

On preempt-rt kernels, a standard spinlock_t is an rt_mutex and can sleep.
Attempting to acquire it during regmap operations like regmap_clear_bits(),
regmap_set_bits(), and regmap_write() while holding a raw_spinlock_t will
cause a kernel panic.

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20260727074234.3761170-1-mikhail.kshevetskiy@iopsys.eu?part=18