From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dmitry Osipenko Date: Thu, 28 Oct 2021 21:58:32 +0000 Subject: Re: [PATCH v2 08/45] kernel: Add combined power-off+restart handler call chain API Message-Id: <28560da7-8ab6-3bd5-b4d6-e34b21a9bbb0@gmail.com> List-Id: References: <20211027211715.12671-1-digetx@gmail.com> <20211027211715.12671-9-digetx@gmail.com> In-Reply-To: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 8bit To: "Rafael J. Wysocki" Cc: Thierry Reding , Jonathan Hunter , Lee Jones , Mark Brown , Andrew Morton , Guenter Roeck , Russell King , Daniel Lezcano , Andy Shevchenko , Ulf Hansson , Catalin Marinas , Will Deacon , Guo Ren , Geert Uytterhoeven , Greg Ungerer , Joshua Thompson , Thomas Bogendoerfer , Greentime Hu , Vincent Chen , "James E.J. Bottomley" , Helge Deller , 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 , Linus Walleij , Chen-Yu Tsai , =?UTF-8?Q?Jonathan_Neusch=c3=a4fer?= , Tony Lindgren , Liam Girdwood , Philipp Zabel , Vladimir Zapolskiy , Avi Fishman , Tomer Maimon , Tali Perry , Patrick Venture , Nancy Yuen , Benjamin Fair , Pavel Machek , Linux ARM , Linux Kernel Mailing List , linux-csky@vger.kernel.org, linux-ia64@vger.kernel.org, linux-m68k@lists.linux-m68k.org, linux-mips@vger.kernel.org, linux-parisc@vger.kernel.org, linuxppc-dev , linux-riscv@lists.infradead.org, Linux-sh list , xen-devel@lists.xenproject.org, ACPI Devel Maling List , Linux OMAP Mailing List , openbmc@lists.ozlabs.org, linux-tegra , Linux PM 28.10.2021 12:59, Rafael J. Wysocki пишет: >> +#define RESTART_PRIO_RESERVED 0 >> +#define RESTART_PRIO_DEFAULT 128 >> +#define RESTART_PRIO_HIGH 192 >> >> enum reboot_mode { >> REBOOT_UNDEFINED = -1, >> @@ -49,6 +55,167 @@ int register_restart_handler(struct notifier_block *); >> int unregister_restart_handler(struct notifier_block *); >> void do_kernel_restart(char *cmd); >> >> +/* >> + * Unified poweroff + restart API. >> + */ >> + >> +#define POWEROFF_PRIO_RESERVED 0 >> +#define POWEROFF_PRIO_PLATFORM 1 >> +#define POWEROFF_PRIO_DEFAULT 128 >> +#define POWEROFF_PRIO_HIGH 192 >> +#define POWEROFF_PRIO_FIRMWARE 224 > Also I'm wondering why these particular numbers were chosen, here and above? These values are chosen based on priorities that drivers already use. I looked thorough them all and ended with this scheme that fulfills the needs of the current API users. I'll add these comments in v3: /* * Standard restart priority levels. Intended to be set in the * sys_off_handler.restart_priority field. * * Use `RESTART_PRIO_XXX +- prio` style for additional levels. * * RESTART_PRIO_RESERVED: Falls back to RESTART_PRIO_DEFAULT. * Drivers may leave priority initialized * to zero, to auto-set it to the default level. * * RESTART_PRIO_DEFAULT: Use this for generic handler. * * RESTART_PRIO_HIGH: Use this if you have multiple handlers and * this handler has higher priority than the * default handler. */ /* * Standard power-off priority levels. Intended to be set in the * sys_off_handler.power_off_priority field. * * Use `POWEROFF_PRIO_XXX +- prio` style for additional levels. * * POWEROFF_PRIO_RESERVED: Falls back to POWEROFF_PRIO_DEFAULT. * Drivers may leave priority initialized * to zero, to auto-set it to the default level. * * POWEROFF_PRIO_PLATFORM: Intended to be used by platform-level handler. * Has lowest priority since device drivers are * expected to take over platform handler which * doesn't allow further callback chaining. * * POWEROFF_PRIO_DEFAULT: Use this for generic handler. * * POWEROFF_PRIO_HIGH: Use this if you have multiple handlers and * this handler has higher priority than the * default handler. * * POWEROFF_PRIO_FIRMWARE: Use this if handler uses firmware call. * Has highest priority since firmware is expected * to know best how to power-off hardware properly. */