Work-around: Extract led name from device path
udev rule for leds subsystem in Witherspoon launches a systemd
service file with /sys/class/leds/$name. If the path is
sys-class-leds-rear-fault, systemd service file
interprets it as /sys/class/leds/rear/fault.
However, what is really needed by the service file is
/sys/class/leds/rear-fault.
This is a limitation in current systemd with template argument
containing hyphen.
Short term solution is to extract $name from path
and convert "/" to "-". It would then become:
/sys/class/leds/rear-fault and hence will work.
Refer: systemd/systemd#5072
Change-Id: I0acc11d039650857005ba75810e3ef6bcc4a3934
Signed-off-by: Vishwanatha Subbanna <vishwa@linux.vnet.ibm.com>
diff --git a/controller.cpp b/controller.cpp
index d5728da..f0ba4c2 100644
--- a/controller.cpp
+++ b/controller.cpp
@@ -41,15 +41,23 @@
ExitWithError("Path not specified.", argv);
}
- // Extract the name of LED from path.
- auto index = path.rfind("/");
- if (index == std::string::npos)
- {
- throw std::runtime_error("No Led in " + path);
- }
+ // If the LED has a hyphen in the name like: "one-two", then it gets passed
+ // as /one/two/ as opposed to /one-two to the service file. There is a
+ // change needed in systemd to solve this issue and hence putting in this
+ // work-around.
- // Remove the leading "/"
- auto name = path.substr(index + 1);
+ // Since this application always gets invoked as part of a udev rule,
+ // it is always guaranteed to get /sys/class/leds/one/two
+ // and we can go beyond leds/ to get the actual led name.
+ // Refer: systemd/systemd#5072
+
+ // On an error, this throws an exception and terminates.
+ auto name = path.substr(strlen(DEVPATH));
+
+ // LED names may have a hyphen and that would be an issue for
+ // dbus paths and hence need to convert them to underscores.
+ std::replace(name.begin(), name.end(), '/', '-');
+ path = std::move(DEVPATH + name);
// Convert to lowercase just in case some are not and that
// we follow lowercase all over