lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
Open Source and information security mailing list archives
| ||
|
Message-ID: <CAPDyKFrBSHRmP+CFd7xWXnN6LXKaAtihYv22b60wYsgSShCD+g@mail.gmail.com> Date: Fri, 6 Sep 2024 11:00:09 +0200 From: Ulf Hansson <ulf.hansson@...aro.org> To: Kevin Hilman <khilman@...libre.com> Cc: linux-pm@...r.kernel.org, Nishanth Menon <nm@...com>, Vibhore Vardhan <vibhore@...com>, Dhruva Gole <d-gole@...com>, Akashdeep Kaur <a-kaur@...com>, Sebin Francis <sebin.francis@...com>, Markus Schneider-Pargmann <msp@...libre.com>, linux-arm-kernel@...ts.infradead.org, linux-kernel@...r.kernel.org Subject: Re: [PATCH v2 0/3] pmdomain: ti_sci: collect and send low-power mode constraints On Fri, 6 Sept 2024 at 00:07, Kevin Hilman <khilman@...libre.com> wrote: > > Ulf Hansson <ulf.hansson@...aro.org> writes: > > > On Tue, 20 Aug 2024 at 02:00, Kevin Hilman <khilman@...libre.com> wrote: > >> > >> The latest (10.x) version of the firmware for the PM co-processor (aka > >> device manager, or DM) adds support for a "managed" mode, where the DM > >> firmware will select the specific low power state which is entered > >> when Linux requests a system-wide suspend. > >> > >> In this mode, the DM will always attempt the deepest low-power state > >> available for the SoC. > >> > >> However, Linux (or OSes running on other cores) may want to constrain > >> the DM for certain use cases. For example, the deepest state may have > >> a wakeup/resume latency that is too long for certain use cases. Or, > >> some wakeup-capable devices may potentially be powered off in deep > >> low-power states, but if one of those devices is enabled as a wakeup > >> source, it should not be powered off. > >> > >> These kinds of constraints are are already known in Linux by the use > >> of existing APIs such as per-device PM QoS and device wakeup APIs, but > >> now we need to communicate these constraints to the DM. > >> > >> For TI SoCs with TI SCI support, all DM-managed devices will be > >> connected to a TI SCI PM domain. So the goal of this series is to use > >> the PM domain driver for TI SCI devices to collect constraints, and > >> communicate them to the DM via the new TI SCI APIs. > >> > >> This is all managed by TI SCI PM domain code. No new APIs are needed > >> by Linux drivers. Any device that is managed by TI SCI will be > >> checked for QoS constraints or wakeup capability and the constraints > >> will be collected and sent to the DM. > >> > >> This series depends on the support for the new TI SCI APIs (v10) and > >> was also tested with this series to update 8250_omap serial support > >> for AM62x[2]. > >> > >> [1] https://lore.kernel.org/all/20240801195422.2296347-1-msp@baylibre.com > >> [2] https://lore.kernel.org/all/20240807141227.1093006-1-msp@baylibre.com/ > >> > >> Signed-off-by: Kevin Hilman <khilman@...libre.com> > >> --- > >> Changes in v2: > >> > >> - To simplify this version a bit, drop the pmdomain ->power_off() > >> changes. Constraints only sent during ->suspend() path. The pmdomain > >> path was an optimization that may be added back later. > >> - With the above simplification, drop the extra state variables that > >> had been added to keep track of constraint status. > >> - Link to v1: https://lore.kernel.org/r/20240805-lpm-v6-10-constraints-pmdomain-v1-0-d186b68ded4c@baylibre.com > >> > >> --- > >> Kevin Hilman (3): > >> pmdomain: ti_sci: add per-device latency constraint management > >> pmdomain: ti_sci: add wakeup constraint management > >> pmdomain: ti_sci: handle wake IRQs for IO daisy chain wakeups > >> > >> drivers/pmdomain/ti/ti_sci_pm_domains.c | 76 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ > >> 1 file changed, 76 insertions(+) > >> --- > >> base-commit: ad7eb1b6b92ee0c959a0a6ae846ddadd7a79ea64 > >> change-id: 20240802-lpm-v6-10-constraints-pmdomain-f33df5aef449 > >> > >> Best regards, > >> -- > >> Kevin Hilman <khilman@...libre.com> > > > > Besides a couple of minor things that I have commented on for each > > patch, this looks okay to me! > > > > Taking into account the other series that this depends on, what is the > > best merging strategy? Is it safe for me to take it through my > > pmdomain tree? > > > That other series should be merged shortly, so I will check with > Nishanth (on cc) if he can create an immutable branch/tag that you could > use in your tree. > > It has a build-time dependency on that other series, so I think this is > the best way. > > Alternatively, if you don't expect this to clash with other changes in > your tree, with your ack/reviewed-by, Nishanth could merge this series > via his tree and we could avoid the cross-tree shuffle. At the moment there shouldn't be any clashes I think. Let's use Nishanth's tree and see how it goes. I will ack/review the patches when they are ready. Kind regards Uffe
Powered by blists - more mailing lists