serial: qcom-geni: remove .pm callback, use runtime PM in startup/shutdown

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The driver currently relies on qcom_geni_serial_pm() through the
uart_ops.pm callback to manage runtime PM references. However, the
callback has a void return type, so failures from
pm_runtime_resume_and_get() cannot be propagated to the caller.

As a result, startup() may continue and access hardware even when the
runtime PM resume operation failed, leading to register accesses while
the device is not powered.

Move runtime PM acquisition to qcom_geni_serial_startup() and release it
to qcom_geni_serial_shutdown(). Since startup() can return an error, PM
resume failures are now detected and propagated before any hardware
initialization is performed. The startup/shutdown pair also provides a
natural place to balance runtime PM references for normal port usage.

During probe, uart_add_one_port() may configure the port before any user
opens the TTY, meaning startup() has not yet been called. To keep the
hardware powered during port registration, acquire a runtime PM
reference with pm_runtime_resume_and_get() before uart_add_one_port()
and release it with pm_runtime_put() afterwards.

By moving runtime PM handling out of uart_ops.pm, resume failures are no
longer silently ignored and all hardware accesses are guaranteed to
occur while the device is powered.

Signed-off-by: Praveen Talari <praveen.talari@oss.qualcomm.com>
Link: https://patch.msgid.link/20260720-remove_uart_change_state-v2-1-30153ce4333b@oss.qualcomm.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

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This commit is contained in:

Praveen Talari 2026-07-20 14:27:52 +05:30 • committed by Greg Kroah-Hartman

parent 1145d1a070

commit aee1f94dab

1 changed files with 18 additions and 19 deletions

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drivers/tty/serial/qcom_geni_serial.c

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