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

[Krzysztof Kozlowski <krzk@kernel.org>]

On 18/09/2025 12:55, Praveen Talari wrote:
> Hi Krzysztof,
> 
> On 9/18/2025 5:28 AM, Krzysztof Kozlowski wrote:
>> 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?
> 
> Since Jorge was involved in validating the change, I’ve added him under 
> the Tested-by tag.
> 
> Please correct me if I’m not supposed to add this tag myself.
Yes, it is wrong. You did not receive the tag! Which process or
document, suggested that you can create such tag? I commented on the
patches, so you will add now "Reviewed-by" with my name?

No.


Best regards,
Krzysztof