Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755883Ab1EWDJ2 (ORCPT ); Sun, 22 May 2011 23:09:28 -0400 Received: from rcsinet10.oracle.com ([148.87.113.121]:38864 "EHLO rcsinet10.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753722Ab1EWDJ0 (ORCPT ); Sun, 22 May 2011 23:09:26 -0400 Message-ID: <4DD9CF9E.6000103@oracle.com> Date: Sun, 22 May 2011 20:08:14 -0700 From: Randy Dunlap Organization: Oracle Linux Engineering User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.1.5) Gecko/20091209 Fedora/3.0-3.fc11 Thunderbird/3.0 MIME-Version: 1.0 To: "Rafael J. Wysocki" CC: Linux PM mailing list , Frank Hofmann , LKML , linux-sh@vger.kernel.org, Ralf Baechle , Benjamin Herrenschmidt Subject: Re: [PATCH 3/3] PM / Hibernate: Update kerneldoc comments in hibernate.c References: <201105211408.28671.rjw@sisk.pl> <201105211412.11782.rjw@sisk.pl> In-Reply-To: <201105211412.11782.rjw@sisk.pl> Content-Type: text/plain; charset=GB2312 Content-Transfer-Encoding: 7bit X-Source-IP: rtcsinet21.oracle.com [66.248.204.29] X-CT-RefId: str=0001.0A090204.4DD9CFB0.005A:SCFSTAT5015188,ss=1,pt=DBB_65838,fgs=0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 14986 Lines: 419 On 05/21/11 05:12, Rafael J. Wysocki wrote: > 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 outdated and some of them don't adhere to the kernel's standards.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. Hi Rafael, Several of the functions are missing function parameter notations, as noted below. > Signed-off-by: Rafael J. Wysocki > --- > kernel/power/hibernate.c | 184 ++++++++++++++++++++++++----------------------- > 1 file changed, 94 insertions(+), 90 deletions(-) > > 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. * @platform_mode: > */ > - > 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. * @platform_mode: > */ > - > 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. * @platform_mode: > + * > + * 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. * @platform_mode: > + * > + * 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. * @platform_mode: > + * > + * 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. * @platform_mode: > + * > + * 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. * @platform_mode: > + * > + * 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. * @platform_mode: > */ > - > 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. * @platform_mode: > + * > + * 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. * @platform_mode: > + * > + * 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) > { > Thanks. -- ~Randy *** Remember to use Documentation/SubmitChecklist when testing your code *** -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/