Linux Power Management development
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From: Ulf Hansson <ulf.hansson@linaro.org>
To: Saravana Kannan <saravanak@google.com>,
	Stephen Boyd <sboyd@kernel.org>,
	linux-pm@vger.kernel.org
Cc: "Rafael J . Wysocki" <rafael@kernel.org>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	Michael Grzeschik <m.grzeschik@pengutronix.de>,
	Bjorn Andersson <andersson@kernel.org>,
	Abel Vesa <abel.vesa@linaro.org>,
	Devarsh Thakkar <devarsht@lewv0571a.ent.ti.com>,
	Peng Fan <peng.fan@oss.nxp.com>,
	Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>,
	Johan Hovold <johan@kernel.org>,
	Maulik Shah <maulik.shah@oss.qualcomm.com>,
	Ulf Hansson <ulf.hansson@linaro.org>,
	linux-arm-kernel@lists.infradead.org,
	linux-kernel@vger.kernel.org
Subject: [PATCH 00/11] pmdomain: Add generic ->sync_state() support to genpd
Date: Thu, 17 Apr 2025 16:24:58 +0200	[thread overview]
Message-ID: <20250417142513.312939-1-ulf.hansson@linaro.org> (raw)

If a PM domain (genpd) is powered-on during boot, there is probably a good
reason for it. Therefore it's known to be a bad idea to allow such genpd to be
powered-off before all of its consumer devices have been probed. This series
intends to fix this problem.

We have been discussing these issues at LKML and at various Linux-conferences
in the past. I have therefore tried to include the people I can recall being
involved, but I may have forgotten some (my apologies), feel free to loop them
in.

A few notes:
*)
Even if this looks good, the last patch can't go in without some additional
changes to a couple of existing genpd provider drivers. Typically genpd provider
drivers that implements ->sync_state() need to call of_genpd_sync_state(), but I
will fix this asap, if we think the series makes sense.

*)
Patch 1 -> 3 are just preparatory cleanups. 

*)
I have tested this with QEMU with a bunch of local test-drivers and DT nodes.
Let me know if you want me to share this code too.


Please help review and test!
Finally, a big thanks to Saravana for all the support!

Kind regards
Ulf Hansson


Saravana Kannan (1):
  driver core: Add dev_set_drv_sync_state()

Ulf Hansson (10):
  pmdomain: core: Convert genpd_power_off() to void
  pmdomain: core: Simplify return statement in genpd_power_off()
  pmdomain: core: Use genpd->opp_table to simplify error/remove path
  pmdomain: core: Add a bus and a driver for genpd providers
  pmdomain: core: Use device_set_node() to assign the fwnode too
  pmdomain: core: Add the genpd->dev to the genpd provider bus
  pmdomain: core: Export a common ->sync_state() helper for genpd
    providers
  pmdomain: core: Add internal ->sync_state() support for genpd
    providers
  pmdomain: core: Default to use of_genpd_sync_state() for genpd
    providers
  pmdomain: core: Leave powered-on genpds on until ->sync_state()

 drivers/pmdomain/core.c   | 273 +++++++++++++++++++++++++++++++-------
 include/linux/device.h    |  12 ++
 include/linux/pm_domain.h |  11 ++
 3 files changed, 249 insertions(+), 47 deletions(-)

-- 
2.43.0


             reply	other threads:[~2025-04-17 14:25 UTC|newest]

Thread overview: 33+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2025-04-17 14:24 Ulf Hansson [this message]
2025-04-17 14:24 ` [PATCH 01/11] pmdomain: core: Convert genpd_power_off() to void Ulf Hansson
2025-04-22 13:27   ` Abel Vesa
2025-04-17 14:25 ` [PATCH 02/11] pmdomain: core: Simplify return statement in genpd_power_off() Ulf Hansson
2025-04-22 13:28   ` Abel Vesa
2025-04-17 14:25 ` [PATCH 03/11] pmdomain: core: Use genpd->opp_table to simplify error/remove path Ulf Hansson
2025-04-22 13:33   ` Abel Vesa
2025-04-17 14:25 ` [PATCH 04/11] pmdomain: core: Add a bus and a driver for genpd providers Ulf Hansson
2025-04-22 14:02   ` Abel Vesa
2025-04-23  7:34     ` Ulf Hansson
2025-04-17 14:25 ` [PATCH 05/11] pmdomain: core: Use device_set_node() to assign the fwnode too Ulf Hansson
2025-04-17 20:55   ` Saravana Kannan
2025-04-23  7:30     ` Ulf Hansson
2025-04-22 14:04   ` Abel Vesa
2025-04-17 14:25 ` [PATCH 06/11] pmdomain: core: Add the genpd->dev to the genpd provider bus Ulf Hansson
2025-04-22 14:06   ` Abel Vesa
2025-04-17 14:25 ` [PATCH 07/11] pmdomain: core: Export a common ->sync_state() helper for genpd providers Ulf Hansson
2025-04-22 14:10   ` Abel Vesa
2025-05-07 16:23   ` Dan Carpenter
2025-05-08 10:05     ` Ulf Hansson
2025-04-17 14:25 ` [PATCH 08/11] pmdomain: core: Add internal ->sync_state() support " Ulf Hansson
2025-04-18  0:23   ` Saravana Kannan
2025-04-23  7:58     ` Ulf Hansson
2025-04-17 14:25 ` [PATCH 09/11] driver core: Add dev_set_drv_sync_state() Ulf Hansson
2025-04-22 14:15   ` Abel Vesa
2025-04-17 14:25 ` [PATCH 10/11] pmdomain: core: Default to use of_genpd_sync_state() for genpd providers Ulf Hansson
2025-04-18  0:29   ` Saravana Kannan
2025-04-17 14:25 ` [PATCH 11/11] pmdomain: core: Leave powered-on genpds on until ->sync_state() Ulf Hansson
2025-04-18  0:50   ` Saravana Kannan
2025-04-23  7:46     ` Ulf Hansson
2025-04-18  0:53 ` [PATCH 00/11] pmdomain: Add generic ->sync_state() support to genpd Saravana Kannan
2025-04-24 10:59 ` Tomi Valkeinen
2025-04-25 12:17   ` Ulf Hansson

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