[PATCH] Fix Userspace interface breakage in power/state

Prevent passing invalid values down to the drivers.

Signed-off-by: Pavel Machek <pavel@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 16 insertions, 8 deletions

diff --git a/drivers/base/power/sysfs.c b/drivers/base/power/sysfs.c
index f3a0c562bc..40d7242a07 100644
--- a/drivers/base/power/sysfs.c
+++ b/drivers/base/power/sysfs.c
@@ -27,22 +27,30 @@
 
 static ssize_t state_show(struct device * dev, struct device_attribute *attr, char * buf)
 {
-        return sprintf(buf, "%u\n", dev->power.power_state.event);
+        if (dev->power.power_state.event)
+                return sprintf(buf, "2\n");
+        else
+                return sprintf(buf, "0\n");
 }
 
 static ssize_t state_store(struct device * dev, struct device_attribute *attr, const char * buf, size_t n)
 {
         pm_message_t state;
-        char * rest;
-        int error = 0;
+        int error = -EINVAL;
 
-        state.event = simple_strtoul(buf, &rest, 10);
-        if (*rest)
-                return -EINVAL;
-        if (state.event)
+        state.event = PM_EVENT_SUSPEND;
+        /* Older apps expected to write "3" here - confused with PCI D3 */
+        if ((n == 1) && !strcmp(buf, "3"))
                 error = dpm_runtime_suspend(dev, state);
-        else
+
+        if ((n == 1) && !strcmp(buf, "2"))
+                error = dpm_runtime_suspend(dev, state);
+
+        if ((n == 1) && !strcmp(buf, "0")) {
                 dpm_runtime_resume(dev);
+                error = 0;
+        }
+
         return error ? error : n;
 }