On Thu, Jul 11, 2024 at 10:30:08AM +0200, Mariusz Tkaczyk wrote: > Native PCIe Enclosure Management (NPEM, PCIe r6.1 sec 6.28) allows > managing LED in storage enclosures. NPEM is indication oriented > and it does not give direct access to LED. Although each of > the indications *could* represent an individual LED, multiple > indications could also be represented as a single, > multi-color LED or a single LED blinking in a specific interval. > The specification leaves that open. The specification leaves it open, but isn't there a way to determine how it is implemented? In ACPI, maybe? > Each enabled indication (capability register bit on) is represented as a > ledclass_dev which can be controlled through sysfs. For every ledclass > device only 2 brightness states are allowed: LED_ON (1) or LED_OFF (0). > It is corresponding to NPEM control register (Indication bit on/off). > > Ledclass devices appear in sysfs as child devices (subdirectory) of PCI > device which has an NPEM Extended Capability and indication is enabled > in NPEM capability register. For example, these are leds created for > pcieport "10000:02:05.0" on my setup: > > leds/ > ├── 10000:02:05.0:enclosure:fail > ├── 10000:02:05.0:enclosure:locate > ├── 10000:02:05.0:enclosure:ok > └── 10000:02:05.0:enclosure:rebuild > > They can be also found in "/sys/class/leds" directory. Parent PCIe device > bdf is used to guarantee uniqueness across leds subsystem. > > To enable/disable fail indication "brightness" file can be edited: > echo 1 > ./leds/10000:02:05.0:enclosure:fail/brightness > echo 0 > ./leds/10000:02:05.0:enclosure:fail/brightness Have you considered implemtening this via a led trigger? Something like: echo pcie-enclosure > /sys/class/leds/<LED>/trigger echo 1 >/sys/class/leds/<LED>/fail but properly thought up. Marek
