Re: [PATCH v7 7/8] serial: qcom-geni: Enable PM runtime for serial driver

["Alexey Klimov" <alexey.klimov@linaro.org>]

Hi Praveen,

Hi Praveen,

On Tue Aug 19, 2025 at 8:16 AM BST, Krzysztof Kozlowski wrote:
> On 19/08/2025 08:50, Praveen Talari wrote:
>> Hi Alexey.
>> 
>> Thank you for your patience,

Well, any update on this?



>> On 8/12/2025 3:35 PM, Alexey Klimov wrote:
>>> (c/c Neil and Srini)
>>>
>>> On Mon Jul 21, 2025 at 6:45 PM BST, Praveen Talari wrote:
>>>> The GENI serial driver currently handles power resource management
>>>> through calls to the statically defined geni_serial_resources_on() and
>>>> geni_serial_resources_off() functions. This approach reduces modularity
>>>> and limits support for platforms with diverse power management
>>>> mechanisms, including resource managed by firmware.
>>>>
>>>> Improve modularity and enable better integration with platform-specific
>>>> power management, introduce support for runtime PM. Use
>>>> pm_runtime_resume_and_get() and pm_runtime_put_sync() within the
>>>> qcom_geni_serial_pm() callback to control resource power state
>>>> transitions based on UART power state changes.
>>>>
>>>> Reviewed-by: Bryan O'Donoghue <bryan.odonoghue@linaro.org>
>>>> Signed-off-by: Praveen Talari <quic_ptalari@quicinc.com>
>>>
>>>
>>> This breaks at least RB1 (QRB2210), maybe others.
>>> Currently broken on -master and on linux-next.
>>>
>>> Upon login prompt random parts of kernel seems to be off/failed and
>>> debugging led to udev being stuck:
>>>
>>> [   85.369834] INFO: task kworker/u16:0:12 blocked for more than 42 seconds.
>>> [   85.376699]       Not tainted 6.17.0-rc1-00004-g53e760d89498 #9
>>> [   85.382660] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
>>> [   85.390547] task:kworker/u16:0   state:D stack:0     pid:12    tgid:12    ppid:2      task_flags:0x4208060 flags:0x00000010
>>> [   85.401748] Workqueue: async async_run_entry_fn
>>> [   85.406349] Call trace:
>>> [   85.408828]  __switch_to+0xe8/0x1a0 (T)
>>> [   85.412724]  __schedule+0x290/0x7c0
>>> [   85.416275]  schedule+0x34/0x118
>>> [   85.419554]  rpm_resume+0x14c/0x66c
>>> [   85.423111]  rpm_resume+0x2a4/0x66c
>>> [   85.426647]  rpm_resume+0x2a4/0x66c
>>> [   85.430188]  rpm_resume+0x2a4/0x66c
>>> [   85.433722]  __pm_runtime_resume+0x50/0x9c
>>> [   85.437869]  __driver_probe_device+0x58/0x120
>>> [   85.442287]  driver_probe_device+0x3c/0x154
>>> [   85.446523]  __driver_attach_async_helper+0x4c/0xc0
>>> [   85.451446]  async_run_entry_fn+0x34/0xe0
>>> [   85.455504]  process_one_work+0x148/0x290
>>> [   85.459565]  worker_thread+0x2c4/0x3e0
>>> [   85.463368]  kthread+0x118/0x1c0
>>> [   85.466651]  ret_from_fork+0x10/0x20
>>> [   85.470337] INFO: task irq/92-4a8c000.:71 blocked for more than 42 seconds.
>>> [   85.477351]       Not tainted 6.17.0-rc1-00004-g53e760d89498 #9
>>> [   85.483323] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
>>> [   85.491195] task:irq/92-4a8c000. state:D stack:0     pid:71    tgid:71    ppid:2      task_flags:0x208040 flags:0x00000010
>>> [   85.502290] Call trace:
>>> [   85.504786]  __switch_to+0xe8/0x1a0 (T)
>>> [   85.508687]  __schedule+0x290/0x7c0
>>> [   85.512231]  schedule+0x34/0x118
>>> [   85.515504]  __synchronize_irq+0x60/0xa0
>>> [   85.519483]  disable_irq+0x3c/0x4c
>>> [   85.522929]  msm_pinmux_set_mux+0x3a8/0x44c
>>> [   85.527167]  pinmux_enable_setting+0x1c4/0x28c
>>> [   85.531665]  pinctrl_commit_state+0xa0/0x260
>>> [   85.535989]  pinctrl_pm_select_default_state+0x4c/0xa0
>>> [   85.541182]  geni_se_resources_on+0xd0/0x15c
>>> [   85.545522]  geni_serial_resource_state+0x8c/0xbc
>>> [   85.550282]  qcom_geni_serial_runtime_resume+0x24/0x3c
>>> [   85.555470]  pm_generic_runtime_resume+0x2c/0x44
>>> [   85.560139]  __rpm_callback+0x48/0x1e0
>>> [   85.563949]  rpm_callback+0x74/0x80
>>> [   85.567494]  rpm_resume+0x39c/0x66c
>>> [   85.571040]  __pm_runtime_resume+0x50/0x9c
>>> [   85.575193]  handle_threaded_wake_irq+0x30/0x80
>>> [   85.579771]  irq_thread_fn+0x2c/0xb0
>>> [   85.583443]  irq_thread+0x16c/0x278
>>> [   85.587003]  kthread+0x118/0x1c0
>>> [   85.590283]  ret_from_fork+0x10/0x20
>>> [   85.593943] INFO: task (udev-worker):228 blocked for more than 42 seconds.
>>> [   85.600873]       Not tainted 6.17.0-rc1-00004-g53e760d89498 #9
>>> [   85.606846] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
>>> [   85.614717] task:(udev-worker)   state:D stack:0     pid:228   tgid:228   ppid:222    task_flags:0x400140 flags:0x00000818
>>> [   85.625823] Call trace:
>>> [   85.628316]  __switch_to+0xe8/0x1a0 (T)
>>> [   85.632217]  __schedule+0x290/0x7c0
>>> [   85.635765]  schedule+0x34/0x118
>>> [   85.639044]  async_synchronize_cookie_domain.part.0+0x50/0xa4
>>> [   85.644854]  async_synchronize_full+0x78/0xa0
>>> [   85.649270]  do_init_module+0x190/0x23c
>>> [   85.653154]  load_module+0x1708/0x1ca0
>>> [   85.656952]  init_module_from_file+0x74/0xa0
>>> [   85.661273]  __arm64_sys_finit_module+0x130/0x2f8
>>> [   85.666023]  invoke_syscall+0x48/0x104
>>> [   85.669842]  el0_svc_common.constprop.0+0xc0/0xe0
>>> [   85.674604]  do_el0_svc+0x1c/0x28
>>> [   85.677973]  el0_svc+0x2c/0x84
>>> [   85.681078]  el0t_64_sync_handler+0xa0/0xe4
>>> [   85.685316]  el0t_64_sync+0x198/0x19c
>>> [   85.689032] INFO: task (udev-worker):229 blocked for more than 42 seconds.
>>>
>>>
>>> Usually wifi, all remoteprocs and anything that depends on lpass/pinctrl fail to probe.
>> 
>> May i know what is testcase which you are running on target?
>
> Boot the board?
>
>> what is target?
>
> It is written in original report. Did you even read it?
>
>> Which usecase is this issue occurring in?
>
> Boot?

FWIW, what said above by Krzysztof is correct, there is no usecase, just booting the board.

Best regards,
Alexey