From mboxrd@z Thu Jan 1 00:00:00 1970 From: Helge Deller Date: Wed, 16 Feb 2022 20:30:26 +0000 Subject: Re: [PATCH v6 00/21] Introduce power-off+restart call chain API Message-Id: List-Id: References: <20220130233718.21544-1-digetx@gmail.com> <635e8121-fca4-580c-6af5-d9317a2eee1b@gmail.com> In-Reply-To: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 8bit To: "Rafael J. Wysocki" , Dmitry Osipenko Cc: Linux Kernel Mailing List , linux-csky@vger.kernel.org, linux-ia64@vger.kernel.org, linux-m68k@lists.linux-m68k.org, "open list:BROADCOM NVRAM DRIVER" , linux-parisc@vger.kernel.org, linux-riscv@lists.infradead.org, Linux-sh list , xen-devel@lists.xenproject.org, ACPI Devel Maling List , Linux PM , linux-tegra , Thierry Reding , Jonathan Hunter , Russell King , Catalin Marinas , Will Deacon , Guo Ren , Geert Uytterhoeven , Greg Ungerer , Joshua Thompson , Thomas Bogendoerfer , Sebastian Reichel , Linus Walleij , Philipp Zabel , Greentime Hu , Vincent Chen , "James E.J. Bottomley" , Michael Ellerman , Benjamin Herrenschmidt , Paul Mackerras , Paul Walmsley , Palmer Dabbelt , Albert Ou , Yoshinori Sato , Rich Felker , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , the arch/x86 maintainers , "H. Peter Anvin" , Boris Ostrovsky , Juergen Gross , Stefano Stabellini , Len Brown , Santosh Shilimkar , Krzysztof Kozlowski , Liam Girdwood , Mark Brown , Pavel Machek , Lee Jones , Andrew Morton , Guenter Roeck , Daniel Lezcano , Andy Shevchenko , Ulf Hansson , alankao@andestech.com, "K . C . Kuen-Chern Lin" , =?UTF-8?B?TWljaGHFgiBNaXJvc8WCYXc=?= On 2/16/22 13:25, Rafael J. Wysocki wrote: > On Tue, Feb 15, 2022 at 11:00 PM Dmitry Osipenko wrote: >> >> 31.01.2022 02:36, Dmitry Osipenko пишет: >>> Problem >>> ------- >>> >>> SoC devices require power-off call chaining functionality from kernel. >>> We have a widely used restart chaining provided by restart notifier API, >>> but nothing for power-off. >>> >>> Solution >>> -------- >>> >>> Introduce new API that provides both restart and power-off call chains. >>> >>> Why combine restart with power-off? Because drivers often do both. >>> More practical to have API that provides both under the same roof. >>> >>> The new API is designed with simplicity and extensibility in mind. >>> It's built upon the existing restart and reboot APIs. The simplicity >>> is in new helper functions that are convenient for drivers. The >>> extensibility is in the design that doesn't hardcode callback >>> arguments, making easy to add new parameters and remove old. >>> >>> This is a third attempt to introduce the new API. First was made by >>> Guenter Roeck back in 2014, second was made by Thierry Reding in 2017. >>> In fact the work didn't stop and recently arm_pm_restart() was removed >>> from v5.14 kernel, which was a part of preparatory work started by >>> Guenter Roeck. I took into account experience and ideas from the >>> previous attempts, extended and polished them. >> >> >> Rafael and all, do you see anything critical that needs to be improved >> in this v6? >> >> Will be great if you could take this patchset via the power tree if it >> looks okay, or give an ack. > > I need some more time for this, sorry. > > I'm a bit concerned about seeing no response to this set from anyone. > > It looks like multiple platforms may be affected by it in principle, > so doesn't anyone care? I did looked into the whole patch set after applying it locally. While I agree a new combined API is good, and the beginning looked promising, after some time I started to ask myself if the whole infrastructure might be a little overdesigned. Anyway, I tested it and it works for me on parisc. And it's probably better than what we have today. Helge