power management: change /sys/power/disk display

Change /sys/power/disk to display all valid modes as well as the currently
selected one in a fashion known from the LED subsystem.

This changes userspace API, but it is apparently not used much (we asked
some userspace developers)

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Acked-by: "Rafael J. Wysocki" <rjw@sisk.pl>
Acked-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/Documentation/power/interface.txt b/Documentation/power/interface.txt
index 8c5b41bf3f363e386181f8adccd33cc2b97f81b2..fd5192a8fa8abebd12fe86aefd99404978d88f34 100644 (file)
--- a/Documentation/power/interface.txt
+++ b/Documentation/power/interface.txt
@@ -34,8 +34,12 @@ for 5 seconds, resume devices, unfreeze tasks and enable nonboot CPUs.  Then,
 we are able to look in the log messages and work out, for example, which code
 is being slow and which device drivers are misbehaving.
 
-Reading from this file will display what the mode is currently set
-to. Writing to this file will accept one of
+Reading from this file will display all supported modes and the currently
+selected one in brackets, for example
+
+       [shutdown] reboot test testproc
+
+Writing to this file will accept one of
 
        'platform' (only if the platform supports it)
        'shutdown'

diff --git a/kernel/power/disk.c b/kernel/power/disk.c
index e518379b667a77a6df39321c3bed94dcafbb1f2d..06331374d8624627e4071ca5df6b70cdf16c190b 100644 (file)
--- a/kernel/power/disk.c
+++ b/kernel/power/disk.c
@@ -350,7 +350,34 @@ static const char * const pm_disk_modes[] = {
 
 static ssize_t disk_show(struct kset *kset, char *buf)
 {
-       return sprintf(buf, "%s\n", pm_disk_modes[pm_disk_mode]);
+       int i;
+       char *start = buf;
+
+       for (i = PM_DISK_PLATFORM; i < PM_DISK_MAX; i++) {
+               if (!pm_disk_modes[i])
+                       continue;
+               switch (i) {
+               case PM_DISK_SHUTDOWN:
+               case PM_DISK_REBOOT:
+               case PM_DISK_TEST:
+               case PM_DISK_TESTPROC:
+                       break;
+               default:
+                       if (pm_ops && pm_ops->enter &&
+                           (i == pm_ops->pm_disk_mode))
+                               break;
+                       /* not a valid mode, continue with loop */
+                       continue;
+               }
+               if (i == pm_disk_mode)
+                       buf += sprintf(buf, "[%s]", pm_disk_modes[i]);
+               else
+                       buf += sprintf(buf, "%s", pm_disk_modes[i]);
+               if (i+1 != PM_DISK_MAX)
+                       buf += sprintf(buf, " ");
+       }
+       buf += sprintf(buf, "\n");
+       return buf-start;
 }