diff options
author | Rafael J. Wysocki <rjw@sisk.pl> | 2011-06-18 13:53:57 -0400 |
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committer | Rafael J. Wysocki <rjw@sisk.pl> | 2011-06-21 17:19:15 -0400 |
commit | 78420884e680da8fbc3240de2d3106437042381e (patch) | |
tree | e527e3f745a6c69689fbe66c6a85a08cffa0e778 /Documentation/power | |
parent | 129b656a0de9a229a72fe4bb6bacd134a1477b44 (diff) |
PM: Update documentation regarding sysdevs
The part of Documentation/power/devices.txt regarding sysdevs is not
valid any more after commit 2e711c04dbbf7a7732a3f7073b1fc285d12b369d
(PM: Remove sysdev suspend, resume and shutdown operations), so
remove it.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Diffstat (limited to 'Documentation/power')
-rw-r--r-- | Documentation/power/devices.txt | 26 |
1 files changed, 0 insertions, 26 deletions
diff --git a/Documentation/power/devices.txt b/Documentation/power/devices.txt index 88880839ece4..ff923fe67d98 100644 --- a/Documentation/power/devices.txt +++ b/Documentation/power/devices.txt | |||
@@ -549,32 +549,6 @@ callbacks. The other platforms need not implement it or take it into account | |||
549 | in any way. | 549 | in any way. |
550 | 550 | ||
551 | 551 | ||
552 | System Devices | ||
553 | -------------- | ||
554 | System devices (sysdevs) follow a slightly different API, which can be found in | ||
555 | |||
556 | include/linux/sysdev.h | ||
557 | drivers/base/sys.c | ||
558 | |||
559 | System devices will be suspended with interrupts disabled, and after all other | ||
560 | devices have been suspended. On resume, they will be resumed before any other | ||
561 | devices, and also with interrupts disabled. These things occur in special | ||
562 | "sysdev_driver" phases, which affect only system devices. | ||
563 | |||
564 | Thus, after the suspend_noirq (or freeze_noirq or poweroff_noirq) phase, when | ||
565 | the non-boot CPUs are all offline and IRQs are disabled on the remaining online | ||
566 | CPU, then a sysdev_driver.suspend phase is carried out, and the system enters a | ||
567 | sleep state (or a system image is created). During resume (or after the image | ||
568 | has been created or loaded) a sysdev_driver.resume phase is carried out, IRQs | ||
569 | are enabled on the only online CPU, the non-boot CPUs are enabled, and the | ||
570 | resume_noirq (or thaw_noirq or restore_noirq) phase begins. | ||
571 | |||
572 | Code to actually enter and exit the system-wide low power state sometimes | ||
573 | involves hardware details that are only known to the boot firmware, and | ||
574 | may leave a CPU running software (from SRAM or flash memory) that monitors | ||
575 | the system and manages its wakeup sequence. | ||
576 | |||
577 | |||
578 | Device Low Power (suspend) States | 552 | Device Low Power (suspend) States |
579 | --------------------------------- | 553 | --------------------------------- |
580 | Device low-power states aren't standard. One device might only handle | 554 | Device low-power states aren't standard. One device might only handle |