From patchwork Sat May 21 12:12:11 2011 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Rafael Wysocki X-Patchwork-Id: 805762 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by demeter1.kernel.org (8.14.4/8.14.3) with ESMTP id p4LCD1AD014779 for ; Sat, 21 May 2011 12:13:01 GMT Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755778Ab1EUMMl (ORCPT ); Sat, 21 May 2011 08:12:41 -0400 Received: from ogre.sisk.pl ([217.79.144.158]:44576 "EHLO ogre.sisk.pl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755686Ab1EUMMQ (ORCPT ); Sat, 21 May 2011 08:12:16 -0400 Received: from localhost (localhost.localdomain [127.0.0.1]) by ogre.sisk.pl (Postfix) with ESMTP id 28EC61A790A; Sat, 21 May 2011 14:01:58 +0200 (CEST) Received: from ogre.sisk.pl ([127.0.0.1]) by localhost (ogre.sisk.pl [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id 24821-05; Sat, 21 May 2011 14:01:29 +0200 (CEST) Received: from ferrari.rjw.lan (220-bem-13.acn.waw.pl [82.210.184.220]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by ogre.sisk.pl (Postfix) with ESMTP id 749421A95A0; Sat, 21 May 2011 14:01:29 +0200 (CEST) From: "Rafael J. Wysocki" To: Linux PM mailing list Subject: [PATCH 3/3] PM / Hibernate: Update kerneldoc comments in hibernate.c Date: Sat, 21 May 2011 14:12:11 +0200 User-Agent: KMail/1.13.6 (Linux/2.6.39+; KDE/4.6.0; x86_64; ; ) Cc: Frank Hofmann , LKML , linux-sh@vger.kernel.org, Ralf Baechle , Benjamin Herrenschmidt , Randy Dunlap References: <201105211408.28671.rjw@sisk.pl> In-Reply-To: <201105211408.28671.rjw@sisk.pl> MIME-Version: 1.0 Message-Id: <201105211412.11782.rjw@sisk.pl> X-Virus-Scanned: amavisd-new at ogre.sisk.pl using MkS_Vir for Linux Sender: linux-sh-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-sh@vger.kernel.org X-Greylist: IP, sender and recipient auto-whitelisted, not delayed by milter-greylist-4.2.6 (demeter1.kernel.org [140.211.167.41]); Sat, 21 May 2011 12:13:01 +0000 (UTC) From: Rafael J. Wysocki Some of the kerneldoc comments in kernel/power/hibernate.c are outdated and some of them don't adhere to the kernel's standards. Update them and make them look in a consistent way. Signed-off-by: Rafael J. Wysocki --- kernel/power/hibernate.c | 184 ++++++++++++++++++++++++----------------------- 1 file changed, 94 insertions(+), 90 deletions(-) -- To unsubscribe from this list: send the line "unsubscribe linux-sh" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Index: linux-2.6/kernel/power/hibernate.c =================================================================== --- linux-2.6.orig/kernel/power/hibernate.c +++ linux-2.6/kernel/power/hibernate.c @@ -55,10 +55,9 @@ static int hibernation_mode = HIBERNATIO static const struct platform_hibernation_ops *hibernation_ops; /** - * hibernation_set_ops - set the global hibernate operations - * @ops: the hibernation operations to use in subsequent hibernation transitions + * hibernation_set_ops - Set the global hibernate operations. + * @ops: Hibernation operations to use in subsequent hibernation transitions. */ - void hibernation_set_ops(const struct platform_hibernation_ops *ops) { if (ops && !(ops->begin && ops->end && ops->pre_snapshot @@ -115,10 +114,8 @@ static int hibernation_test(int level) { #endif /* !CONFIG_PM_DEBUG */ /** - * platform_begin - tell the platform driver that we're starting - * hibernation + * platform_begin - Use platform driver to start hibernation. */ - static int platform_begin(int platform_mode) { return (platform_mode && hibernation_ops) ? @@ -126,10 +123,8 @@ static int platform_begin(int platform_m } /** - * platform_end - tell the platform driver that we've entered the - * working state + * platform_end - Use platform driver to finish transition to the working state. */ - static void platform_end(int platform_mode) { if (platform_mode && hibernation_ops) @@ -137,8 +132,10 @@ static void platform_end(int platform_mo } /** - * platform_pre_snapshot - prepare the machine for hibernation using the - * platform driver if so configured and return an error code if it fails + * platform_pre_snapshot - Call platform to prepare the machine for hibernation. + * + * Use the platform driver to prepare the system for creating a hibernate image, + * if so configured, and return an error code if that fails. */ static int platform_pre_snapshot(int platform_mode) @@ -148,10 +145,13 @@ static int platform_pre_snapshot(int pla } /** - * platform_leave - prepare the machine for switching to the normal mode - * of operation using the platform driver (called with interrupts disabled) + * platform_leave - Use platform to prepare a transition to the working state. + * + * Use the platform driver prepare to prepare the machine for switching to the + * normal mode of operation. + * + * This routine is called on one CPU with interrupts disabled. */ - static void platform_leave(int platform_mode) { if (platform_mode && hibernation_ops) @@ -159,10 +159,13 @@ static void platform_leave(int platform_ } /** - * platform_finish - switch the machine to the normal mode of operation - * using the platform driver (must be called after platform_prepare()) + * platform_finish - Use platform to switch the system to the working state. + * + * Use the platform driver to switch the machine to the normal mode of + * operation. + * + * This routine must be called after platform_prepare(). */ - static void platform_finish(int platform_mode) { if (platform_mode && hibernation_ops) @@ -170,11 +173,14 @@ static void platform_finish(int platform } /** - * platform_pre_restore - prepare the platform for the restoration from a - * hibernation image. If the restore fails after this function has been - * called, platform_restore_cleanup() must be called. + * platform_pre_restore - Prepare for hibernate image restoration. + * + * Use the platform driver to prepare the system for resume from a hibernation + * image. + * + * If the restore fails after this function has been called, + * platform_restore_cleanup() must be called. */ - static int platform_pre_restore(int platform_mode) { return (platform_mode && hibernation_ops) ? @@ -182,12 +188,15 @@ static int platform_pre_restore(int plat } /** - * platform_restore_cleanup - switch the platform to the normal mode of - * operation after a failing restore. If platform_pre_restore() has been - * called before the failing restore, this function must be called too, - * regardless of the result of platform_pre_restore(). + * platform_restore_cleanup - Switch to the working state after failing restore. + * + * Use the platform driver to switch the system to the normal mode of operation + * after a failing restore. + * + * If platform_pre_restore() has been called before the failing restore, this + * function must be called too, regardless of the result of + * platform_pre_restore(). */ - static void platform_restore_cleanup(int platform_mode) { if (platform_mode && hibernation_ops) @@ -195,10 +204,8 @@ static void platform_restore_cleanup(int } /** - * platform_recover - recover the platform from a failure to suspend - * devices. + * platform_recover - Recover the platform from a failure to suspend devices. */ - static void platform_recover(int platform_mode) { if (platform_mode && hibernation_ops && hibernation_ops->recover) @@ -206,13 +213,12 @@ static void platform_recover(int platfor } /** - * swsusp_show_speed - print the time elapsed between two events. - * @start: Starting event. - * @stop: Final event. - * @nr_pages - number of pages processed between @start and @stop - * @msg - introductory message to print + * swsusp_show_speed - Print time elapsed between two events during hibernation. + * @start: Starting event. + * @stop: Final event. + * @nr_pages: Number of memory pages processed between @start and @stop. + * @msg: Additional diagnostic message to print. */ - void swsusp_show_speed(struct timeval *start, struct timeval *stop, unsigned nr_pages, char *msg) { @@ -235,11 +241,13 @@ void swsusp_show_speed(struct timeval *s } /** - * create_image - freeze devices that need to be frozen with interrupts - * off, create the hibernation image and thaw those devices. Control - * reappears in this routine after a restore. + * create_image - Create a hibernation image. + * + * Execute device drivers' .freeze_noirq() callbacks, create a hibernation image + * and execute the drivers' .thaw_noirq() callbacks. + * + * Control reappears in this routine after the subsequent restore. */ - static int create_image(int platform_mode) { int error; @@ -304,14 +312,11 @@ static int create_image(int platform_mod } /** - * hibernation_snapshot - quiesce devices and create the hibernation - * snapshot image. - * @platform_mode - if set, use the platform driver, if available, to - * prepare the platform firmware for the power transition. + * hibernation_snapshot - Quiesce devices and create a hibernation image. + * @platform_mode: If set, use platform driver to prepare for the transition. * - * Must be called with pm_mutex held + * This routine must be called with pm_mutex held. */ - int hibernation_snapshot(int platform_mode) { pm_message_t msg = PMSG_RECOVER; @@ -371,13 +376,13 @@ int hibernation_snapshot(int platform_mo } /** - * resume_target_kernel - prepare devices that need to be suspended with - * interrupts off, restore the contents of highmem that have not been - * restored yet from the image and run the low level code that will restore - * the remaining contents of memory and switch to the just restored target - * kernel. + * resume_target_kernel - Restore system state from a hibernation image. + * + * Execute device drivers' .freeze_noirq() callbacks, restore the contents of + * highmem that have not been restored yet from the image and run the low-level + * code that will restore the remaining contents of memory and switch to the + * just restored target kernel. */ - static int resume_target_kernel(bool platform_mode) { int error; @@ -445,14 +450,12 @@ static int resume_target_kernel(bool pla } /** - * hibernation_restore - quiesce devices and restore the hibernation - * snapshot image. If successful, control returns in hibernation_snaphot() - * @platform_mode - if set, use the platform driver, if available, to - * prepare the platform firmware for the transition. + * hibernation_restore - Quiesce devices and restore from a hibernation image. + * @platform_mode: If set, use platform driver to prepare for the transition. * - * Must be called with pm_mutex held + * This routine must be called with pm_mutex held. If it is successful, control + * reappears in the restored target kernel in hibernation_snaphot(). */ - int hibernation_restore(int platform_mode) { int error; @@ -472,10 +475,8 @@ int hibernation_restore(int platform_mod } /** - * hibernation_platform_enter - enter the hibernation state using the - * platform driver (if available) + * hibernation_platform_enter - Power off the system using the platform driver. */ - int hibernation_platform_enter(void) { int error; @@ -546,12 +547,12 @@ int hibernation_platform_enter(void) } /** - * power_down - Shut the machine down for hibernation. + * power_down - Shut the machine down for hibernation. * - * Use the platform driver, if configured so; otherwise try - * to power off or reboot. + * Use the platform driver, if configured, to put the system into the sleep + * state corresponding to hibernation, or try to power it off or reboot, + * depending on the value of hibernation_mode. */ - static void power_down(void) { switch (hibernation_mode) { @@ -588,9 +589,8 @@ static int prepare_processes(void) } /** - * hibernate - The granpappy of the built-in hibernation management + * hibernate - Carry out system hibernation, including saving the image. */ - int hibernate(void) { int error; @@ -668,17 +668,20 @@ int hibernate(void) /** - * software_resume - Resume from a saved image. + * software_resume - Resume from a saved hibernation image. + * + * This routine is called as a late initcall, when all devices have been + * discovered and initialized already. * - * Called as a late_initcall (so all devices are discovered and - * initialized), we call swsusp to see if we have a saved image or not. - * If so, we quiesce devices, the restore the saved image. We will - * return above (in hibernate() ) if everything goes well. - * Otherwise, we fail gracefully and return to the normally - * scheduled program. + * The image reading code is called to see if there is a hibernation image + * available for reading. If that is the case, devices are quiesced and the + * contents of memory is restored from the saved image. * + * If this is successful, control reappears in the restored target kernel in + * hibernation_snaphot() which returns to hibernate(). Otherwise, the routine + * attempts to recover gracefully and make the kernel return to the normal mode + * of operation. */ - static int software_resume(void) { int error; @@ -808,21 +811,17 @@ static const char * const hibernation_mo [HIBERNATION_TESTPROC] = "testproc", }; -/** - * disk - Control hibernation mode +/* + * /sys/power/disk - Control hibernation mode. * - * Suspend-to-disk can be handled in several ways. We have a few options - * for putting the system to sleep - using the platform driver (e.g. ACPI - * or other hibernation_ops), powering off the system or rebooting the - * system (for testing) as well as the two test modes. - * - * The system can support 'platform', and that is known a priori (and - * encoded by the presence of hibernation_ops). However, the user may - * choose 'shutdown' or 'reboot' as alternatives, as well as one fo the - * test modes, 'test' or 'testproc'. + * Hibernation can be handled in several ways. There are a few different ways + * to put the system into the sleep state: using the platform driver (e.g. ACPI + * or other hibernation_ops), powering it off or rebooting it (for testing + * mostly), or using one of the two available test modes. * - * show() will display what the mode is currently set to. - * store() will accept one of + * The sysfs file /sys/power/disk provides an interface for selecting the + * hibernation mode to use. Reading from this file causes the available modes + * to be printed. There are 5 modes that can be supported: * * 'platform' * 'shutdown' @@ -830,8 +829,14 @@ static const char * const hibernation_mo * 'test' * 'testproc' * - * It will only change to 'platform' if the system - * supports it (as determined by having hibernation_ops). + * If a platform hibernation driver is in use, 'platform' will be supported + * and will be used by default. Otherwise, 'shutdown' will be used by default. + * The selected option (i.e. the one corresponding to the current value of + * hibernation_mode) is enclosed by a square bracket. + * + * To select a given hibernation mode it is necessary to write the mode's + * string representation (as returned by reading from /sys/power/disk) back + * into /sys/power/disk. */ static ssize_t disk_show(struct kobject *kobj, struct kobj_attribute *attr, @@ -864,7 +869,6 @@ static ssize_t disk_show(struct kobject return buf-start; } - static ssize_t disk_store(struct kobject *kobj, struct kobj_attribute *attr, const char *buf, size_t n) {