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: <7hplphah5w.fsf@baylibre.com> Date: Thu, 05 Sep 2024 15:07:23 -0700 From: Kevin Hilman <khilman@...libre.com> To: Ulf Hansson <ulf.hansson@...aro.org> 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 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. Either way will work. Up to you. Kevin
Powered by blists - more mailing lists