kernel/linux.git/drivers/pmdomain/core.c, branch v6.18.35

pmdomain: core: Fix detach procedure for virtual devices in genpd

2026-05-14T13:30:20+00:00

commit 26735dfdd8930d9ef1fa92e590a9bf77726efdf6 upstream. If a device is attached to a PM domain through genpd_dev_pm_attach_by_id(), genpd calls pm_runtime_enable() for the corresponding virtual device that it registers. While this avoids boilerplate code in drivers, there is no corresponding call to pm_runtime_disable() in genpd_dev_pm_detach(). This means these virtual devices are typically detached from its genpd, while runtime PM remains enabled for them, which is not how things are designed to work. In worst cases it may lead to critical errors, like a NULL pointer dereference bug in genpd_runtime_suspend(), which was recently reported. For another case, we may end up keeping an unnecessary vote for a performance state for the device. To fix these problems, let's add this missing call to pm_runtime_disable() in genpd_dev_pm_detach(). Reported-by: Geert Uytterhoeven Closes: https://lore.kernel.org/all/CAMuHMdWapT40hV3c+CSBqFOW05aWcV1a6v_NiJYgoYi0i9_PDQ@mail.gmail.com/ Fixes: 3c095f32a92b ("PM / Domains: Add support for multi PM domains per device to genpd") Cc: stable@vger.kernel.org Tested-by: Geert Uytterhoeven Signed-off-by: Ulf Hansson Signed-off-by: Greg Kroah-Hartman

pmdomain: core: Restore behaviour for disabling unused PM domains

2025-09-11T10:36:14+00:00

Recent changes to genpd prevents those PM domains being powered-on during initialization from being powered-off during the boot sequence. Based upon whether CONFIG_PM_CONFIG_PM_GENERIC_DOMAINS_OF is set of not, genpd relies on the sync_state mechanism or the genpd_power_off_unused() (which is a late_initcall_sync), to understand when it's okay to allow these PM domains to be powered-off. This new behaviour in genpd has lead to problems on different platforms. Let's therefore restore the behavior of genpd_power_off_unused(). Moreover, let's introduce GENPD_FLAG_NO_STAY_ON, to allow genpd OF providers to opt-out from the new behaviour. Link: https://lore.kernel.org/all/20250701114733.636510-1-ulf.hansson@linaro.org/ Reported-by: Geert Uytterhoeven Link: https://lore.kernel.org/all/20250902-rk3576-lockup-regression-v1-1-c4a0c9daeb00@collabora.com/ Reported-by: Nicolas Frattaroli Fixes: 0e789b491ba0 ("pmdomain: core: Leave powered-on genpds on until sync_state") Fixes: 13a4b7fb6260 ("pmdomain: core: Leave powered-on genpds on until late_initcall_sync") Tested-by: Heiko Stuebner Reviewed-by: Geert Uytterhoeven Tested-by: Geert Uytterhoeven Signed-off-by: Ulf Hansson

pmdomain: core: introduce dev_pm_genpd_is_on()

2025-07-16T18:54:27+00:00

This helper function returns the current power status of a given generic power domain. As example, remoteproc/imx_rproc.c can now use this function to check the power status of the remote core to properly set "attached" or "offline" modes. Suggested-by: Ulf Hansson Reviewed-by: Bjorn Andersson Reviewed-by: Peng Fan Signed-off-by: Hiago De Franco Link: https://lore.kernel.org/r/20250629172512.14857-2-hiagofranco@gmail.com Signed-off-by: Ulf Hansson

pmdomain: core: Leave powered-on genpds on until sync_state

2025-07-09T11:29:57+00:00

Powering-off a genpd that was on during boot, before all of its consumer devices have been probed, is certainly prone to problems. For OF based platforms we can rely on using the sync_state mechanism that the fw_devlink provides, to understand when all consumers for a genpd provider have been probed. Let's therefore prevent these genpds from being powered-off until the ->sync_state() callback gets called. Note that, for non-OF based platform we will keep relying on the late_initcall_sync, which seems to be the best we can do for now. Suggested-by: Saravana Kannan Tested-by: Hiago De Franco # Colibri iMX8X Tested-by: Tomi Valkeinen # TI AM62A,Xilinx ZynqMP ZCU106 Signed-off-by: Ulf Hansson Link: https://lore.kernel.org/r/20250701114733.636510-23-ulf.hansson@linaro.org

pmdomain: core: Leave powered-on genpds on until late_initcall_sync

2025-07-09T11:29:53+00:00

Powering-off a genpd that was on during boot, before all of its consumer devices have been probed, is certainly prone to problems. As a step to improve this situation, let's prevent these genpds from being powered-off until genpd_power_off_unused() gets called, which is a late_initcall_sync(). Note that, this still doesn't guarantee that all the consumer devices has been probed before we allow to power-off the genpds. Yet, this should be a step in the right direction. Suggested-by: Saravana Kannan Tested-by: Hiago De Franco # Colibri iMX8X Tested-by: Tomi Valkeinen # TI AM62A,Xilinx ZynqMP ZCU106 Signed-off-by: Ulf Hansson Link: https://lore.kernel.org/r/20250701114733.636510-22-ulf.hansson@linaro.org

pmdomain: core: Default to use of_genpd_sync_state() for genpd providers

2025-07-09T11:29:50+00:00

Unless the typical platform driver that act as genpd provider, has its own ->sync_state() callback implemented let's default to use of_genpd_sync_state(). More precisely, while adding a genpd OF provider let's assign the ->sync_state() callback, in case the fwnode has a device and its driver doesn't have the ->sync_state() set already. In this way the typical platform driver doesn't need to assign ->sync_state(), unless it has some additional things to manage beyond genpds. Suggested-by: Saravana Kannan Tested-by: Hiago De Franco # Colibri iMX8X Tested-by: Tomi Valkeinen # TI AM62A,Xilinx ZynqMP ZCU106 Signed-off-by: Ulf Hansson Link: https://lore.kernel.org/r/20250701114733.636510-21-ulf.hansson@linaro.org

pmdomain: core: Add common ->sync_state() support for genpd providers

2025-07-09T11:29:41+00:00

If the genpd provider's fwnode doesn't have an associated struct device with it, we can make use of the generic genpd->dev and it corresponding driver internally in genpd to manage ->sync_state(). More precisely, while adding a genpd OF provider let's check if the fwnode has a device and if not, make the preparation to handle ->sync_state() internally through the genpd_provider_driver and the genpd_provider_bus. Note that, genpd providers may opt out from this behaviour by setting the GENPD_FLAG_NO_SYNC_STATE config options for the genpds in question. Suggested-by: Saravana Kannan Tested-by: Hiago De Franco # Colibri iMX8X Tested-by: Tomi Valkeinen # TI AM62A,Xilinx ZynqMP ZCU106 Signed-off-by: Ulf Hansson Link: https://lore.kernel.org/r/20250701114733.636510-19-ulf.hansson@linaro.org

pmdomain: core: Export a common ->sync_state() helper for genpd providers

2025-07-09T11:28:57+00:00

In some cases the typical platform driver that act as genpd provider, may need its own ->sync_state() callback to manage various things. In this regards, the provider most likely wants to allow its corresponding genpds to be powered-off. For this reason, let's introduce a new genpd helper function, of_genpd_sync_state() that helps genpd provider drivers to achieve this. Suggested-by: Saravana Kannan Reviewed-by: Abel Vesa Tested-by: Hiago De Franco # Colibri iMX8X Tested-by: Tomi Valkeinen # TI AM62A,Xilinx ZynqMP ZCU106 Signed-off-by: Ulf Hansson Link: https://lore.kernel.org/r/20250701114733.636510-8-ulf.hansson@linaro.org

pmdomain: core: Add the genpd->dev to the genpd provider bus

2025-07-09T11:28:53+00:00

To take the next step for a more common handling of the genpd providers, let's add the genpd->dev to the genpd provider bus when registering a genpd OF provider. Also note, to allow us to add devices to the genpd provider bus we need to make sure the bus has been registered first, which is done via a core_initcall. Hence, calls to of_genpd_add_provider_simple|onecell() must be done after the bus has been registered, else they will fail. Suggested-by: Saravana Kannan Reviewed-by: Abel Vesa Tested-by: Hiago De Franco # Colibri iMX8X Tested-by: Tomi Valkeinen # TI AM62A,Xilinx ZynqMP ZCU106 Signed-off-by: Ulf Hansson Link: https://lore.kernel.org/r/20250701114733.636510-7-ulf.hansson@linaro.org

pmdomain: core: Add a bus and a driver for genpd providers

2025-07-09T11:28:48+00:00

When we create a genpd via pm_genpd_init() we are initializing a corresponding struct device for it, but we don't add the device to any bus_type. It has not really been needed as the device is used as cookie to help us manage OPP tables. However, to prepare to make better use of the device, let's add a new genpd provider bus_type and a corresponding genpd provider driver. Subsequent changes will make use of this. Suggested-by: Saravana Kannan Reviewed-by: Abel Vesa Tested-by: Hiago De Franco # Colibri iMX8X Tested-by: Tomi Valkeinen # TI AM62A,Xilinx ZynqMP ZCU106 Signed-off-by: Ulf Hansson Link: https://lore.kernel.org/r/20250701114733.636510-6-ulf.hansson@linaro.org