Re: [PATCH v6 0/4] PM: QoS/pmdomains: support resume latencies for system-wide PM

[Ulf Hansson]

On Thu, Sep 24, 2026 at 10:30 PM Kevin Hilman (TI) <khilman@xxxxxxxxxxxx> wrote:
>
> Currently QoS resume latencies are only considered for runtime PM
> transitions of pmdomains, which remains the default.
>
> In order to also support QoS resume latencies during system-wide PM,
> add a new flag to indicate a resume latency should be used for
> system-wide PM *in addition to* runtime PM.
>
> If a user requires a different latency value for system-wide PM
> compared to runtime PM, then the runtime PM value can be set for
> normal operations, and the system-wide value (and flag) can be set by
> during suspend (for example in a drivers ->prepare() hook) and the
> runtime PM value can be restored after resume (for example, in a
> driver's ->complete() hook.)
>
> To: Rafael J. Wysocki <rafael@xxxxxxxxxx>
> To: Ulf Hansson <ulf.hansson@xxxxxxxxxx>
> To: linux-pm@xxxxxxxxxxxxxxx
>
> Signed-off-by: Kevin Hilman (TI) <khilman@xxxxxxxxxxxx>
> ---
> Changes in v6:
> - use forward declarations instead of include pm_domain.h
> - remove over-detailed locking/lockless comments
> - fix 64-bit math overflow on 32-bit systems
> - drop extra dev_dbg()
> - added Rafael's ack on patch 2
> - Link to v5: https://patch.msgid.link/20260826-topic-lpm-pmdomain-device-constraints-v5-0-28cbf43f7e38@xxxxxxxxxxxx
>
> Changes in v5:
> - update copyright year & author in new header
> - add Reviewed-by tags from Kendall & Abel
> - Link to v4: https://patch.msgid.link/20260819-topic-lpm-pmdomain-device-constraints-v4-0-7ceb095f5474@xxxxxxxxxxxx
>
> Changes in v4:
> - added corresponding WRITE_ONCE() to match READ_ONCE()
> - rebase to v7.2
> - Link to v3: https://patch.msgid.link/20260611-topic-lpm-pmdomain-device-constraints-v3-0-75d69438518b@xxxxxxxxxxxx
>
> Changes in v3:
> - rebased to v7.0
> - fix PREEMPT_RT: add new helper for lockless read of flags for atomic contexts
> - update kerneldoc for genpd_for_each_child() as requested by Ulf
> - Link to v2: https://patch.msgid.link/20260205-topic-lpm-pmdomain-device-constraints-v2-0-61f7be7d35ac@xxxxxxxxxxxx
>
> Changes in v2:
> - drop the userspace interface
> - add genpd helper to iterate over all devices in domain and child domains
> - new flag means latency applies to runtime PM *and* system-wide PM
> - Link to v1: https://patch.msgid.link/20260120-topic-lpm-pmdomain-device-constraints-v1-0-108fc4cfafce@xxxxxxxxxxxx
>
> ---
> Kevin Hilman (TI) (4):
>       PM / QoS: add flag to indicate latency applies system-wide
>       PM / QoS: add lockless read for flags
>       pmdomain: core: add genpd_for_each_child() helper
>       pmdomain: add support system-wide resume latency constraints
>
>  drivers/pmdomain/core.c     | 45 +++++++++++++++++++++++++++++++++++++++++++++
>  drivers/pmdomain/core.h     | 18 ++++++++++++++++++
>  drivers/pmdomain/governor.c | 45 +++++++++++++++++++++++++++++++++++++++++++++
>  include/linux/pm_qos.h      |  9 +++++++++
>  kernel/power/qos.c          |  4 ++--
>  5 files changed, 119 insertions(+), 2 deletions(-)
> ---
> base-commit: 237a1c39e8dfd3e1c6f1f023eea37a48ec04cc63
> change-id: 20260120-topic-lpm-pmdomain-device-constraints-e5e78ce48502
>
> Best regards,
> --
> Kevin Hilman (TI) <khilman@xxxxxxxxxxxx>
>

The v6 applied for next, thanks!

Kind regards
Uffe