On Apr 17, 2016, at 10:27, Lauri Kasanen [off-list ref] wrote:

Hi,

The battery triggers aren't working for some reason, trying to write
them comes back with -EINVAL. I'm on somewhat old kernel, 3.17, but the
relevant parts haven't changed from the commit Frank made in 2014
adding the MAC address to the name.

# cat trigger
none timer heartbeat backlight [default-on]
sony_controller_battery_00:26:5c:31:a2:c8-charging-or-full
sony_controller_battery_00:26:5c:31:a2:c8-charging
sony_controller_battery_00:26:5c:31:a2:c8-full
sony_controller_battery_00:26:5c:31:a2:c8-charging-blink-full-solid

# echo sony_controller_battery_00:26:5c:31:a2:c8-charging-blink-full-solid > trigger
bash: echo: write error: Invalid argument

The shorter triggers do work. Is it something caused by the long name,
or the colons? Do they work for others?

My controller is the Gasia one:
sony 0003:054C:0268.0005: input: USB HID v1.11 Joystick [Gasia Co.,Ltd
PS(R) Gamepad] on usb-0000:00:12.2-2.3/input0

- Lauri

Hi Lauri,

Those trigger names are automatically created by the battery subsystem.  The problem is that in leds.h TRIG_NAME_MAX is only 50 characters and these trigger names are exceeding that by quite a bit, so they are being truncated when passed to the function led_trigger_store() in led_triggers.c.

Either the battery names must be shortened significantly or the max allowed trigger name length has to be increased.  A 50 character limit does seem a bit low when a suffix such as "charging-blink-full-solid” can use half of the character budget by itself.

Regards,
Frank--
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