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Claudiu Beznea
d42c7c6fd6
Calling dev_pm_domain_attach()/dev_pm_domain_detach() in bus driver probe/remove functions can affect system behavior when the drivers attached to the bus use devres-managed resources. Since devres actions may need to access device registers, calling dev_pm_domain_detach() too early, i.e., before these actions complete, can cause failures on some systems. One such example is Renesas RZ/G3S SoC-based platforms. If the device clocks are managed via PM domains, invoking dev_pm_domain_detach() in the bus driver's remove function removes the device's clocks from the PM domain, preventing any subsequent pm_runtime_resume*() calls from enabling those clocks. The second argument of dev_pm_domain_attach() specifies whether the PM domain should be powered on during attachment. Likewise, the second argument of dev_pm_domain_detach() indicates whether the domain should be powered off during detachment. Upcoming changes address the issue described above (initially for the platform bus only) by deferring the call to dev_pm_domain_detach() until after devres_release_all() in device_unbind_cleanup(). The detach_power_off field in struct dev_pm_info stores the detach power off info from the second argument of dev_pm_domain_attach(). Because there are cases where the device's PM domain power-on/off behavior must be conditional (e.g., in i2c_device_probe()), the patch introduces PD_FLAG_ATTACH_POWER_ON and PD_FLAG_DETACH_POWER_OFF flags to be passed to dev_pm_domain_attach(). Finally, dev_pm_domain_attach() and its users are updated to use the newly introduced PD_FLAG_ATTACH_POWER_ON and PD_FLAG_DETACH_POWER_OFF macros. This change is preparatory. Signed-off-by: Claudiu Beznea <[email protected]> Reviewed-by: Mathieu Poirier <[email protected]> Acked-by: Wolfram Sang <[email protected]> # I2C Reviewed-by: Ulf Hansson <[email protected]> Link: https://patch.msgid.link/[email protected] [ rjw: Changelog adjustments ] Signed-off-by: Rafael J. Wysocki <[email protected]>