From: Karel Zak Date: Mon, 26 Jan 2009 21:00:22 +0000 (+0100) Subject: rtcwake: explain supported modes in rtcwake.8 X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=8e88e8fc1efb0428aac984c036ba066ea05f4417;p=util-linux rtcwake: explain supported modes in rtcwake.8 Signed-off-by: Karel Zak --- diff --git a/sys-utils/rtcwake.8 b/sys-utils/rtcwake.8 index a47374dc..55d55a96 100644 --- a/sys-utils/rtcwake.8 +++ b/sys-utils/rtcwake.8 @@ -73,9 +73,32 @@ is the time in seconds since 1970-01-01, 00:00 UTC. Use the \fBdate\fP tool to convert between human-readable time and \fItime_t\fP. .TP \fB-m\fP \fImode\fP | \fB--mode\fP \fImode\fP -Use standby state \fImode\fP. Valid values are \fIstandby\fP, -\fImem\fP, \fIdisk\fP, \fIno\fP (no suspend) and \fIon\fP (for debugging). -The default is \fIstandby\fP. +Use standby state \fImode\fP. Valid values are: +.RS +.TP +.B standby +ACPI state S1. This state offers minimal, though real, power savings, while +providing a very low-latency transition back to a working system. This is the +default mode. +.TP +.B mem +ACPI state S3 (Suspend-to-RAM). This state offers significant power savings as +everything in the system is put into a low-power state, except for memory, +which is placed in self-refresh mode to retain its contents. +.TP +.B disk +ACPI state S4 (Suspend-to-disk). This state offers the greatest power savings, +and can be used even in the absence of low-level platform support for power +management. This state operates similarly to Suspend-to-RAM, but includes a +final step of writing memory contents to disk. +.TP +.B no +Don't suspend. The rtcwake command sets RTC wakeup time only. +.TP +.B on +Don't suspend, but read RTC device until alarm time appears. This mode is +useful for debugging. +.PP .SH NOTES Some PC systems can't currently exit sleep states such as \fImem\fP using only the kernel code accessed by this driver.