Re: [PATCH v2] serial: qcom_geni: Fix pinctrl deadlock on runtime resume

[Krzysztof Kozlowski <krzk@kernel.org>]

On 18/09/2025 03:51, Praveen Talari wrote:
> A stall was observed in disable_irq() during
> pinctrl_pm_select_default_state(), triggered by wakeup IRQ being active
> while the UART port was not yet active. This led to a hang in
> __synchronize_irq(), as shown in the following trace:
> 
> Call trace:
>     __switch_to+0xe0/0x120
>     __schedule+0x39c/0x978
>     schedule+0x5c/0xf8
>     __synchronize_irq+0x88/0xb4
>     disable_irq+0x3c/0x4c
>     msm_pinmux_set_mux+0x508/0x644
>     pinmux_enable_setting+0x190/0x2dc
>     pinctrl_commit_state+0x13c/0x208
>     pinctrl_pm_select_default_state+0x4c/0xa4
>     geni_se_resources_on+0xe8/0x154
>     qcom_geni_serial_runtime_resume+0x4c/0x88
>     pm_generic_runtime_resume+0x2c/0x44
>     __genpd_runtime_resume+0x30/0x80
>     genpd_runtime_resume+0x114/0x29c
>     __rpm_callback+0x48/0x1d8
>     rpm_callback+0x6c/0x78
>     rpm_resume+0x530/0x750
>     __pm_runtime_resume+0x50/0x94
>     handle_threaded_wake_irq+0x30/0x94
>     irq_thread_fn+0x2c/0xa8
>     irq_thread+0x160/0x248
>     kthread+0x110/0x114
>     ret_from_fork+0x10/0x20
> 
> To fix this, wakeup IRQ setup is moved from probe to UART startup,
> ensuring it is only configured when the port is active. Correspondingly,
> the wakeup IRQ is cleared during shutdown. This avoids premature IRQ
> disable during pinctrl setup and prevents the observed stall. The probe
> and remove pathsare simplified by removing redundant wakeup IRQ handling.
> 
> Fixes: 1afa70632c39 ("serial: qcom-geni: Enable PM runtime for serial driver")
> Reported-by: Alexey Klimov <alexey.klimov@linaro.org>
> Closes: https://lore.kernel.org/all/DC0D53ZTNOBU.E8LSD5E5Z8TX@linaro.org/
> Tested-by: Jorge Ramirez <jorge.ramirez@oss.qualcomm.com>

Where did you receive this tag for this patch exactly?

Best regards,
Krzysztof