[Grml] how to turn off / control the usb led display?

Andri Handoko aphandoko at yahoo.com
Fri Jul 13 23:07:53 CEST 2007

Thanks again Mika. Manually unloading module works for some sticks.

  Different USB flash drives behave differently. It seems that the led is
controlled by the firmware/chip in the usb stick. There is no standard in
how to handle the led on the flash drive, since it's not required to have
one (also USB spec doesn't define specific cmds for flash drive). 
  I was able to turn off the Sandisk micro drive led by removing the
usb_storage module ("rmmod usb_storage").  But the same action with an
unknown-brand 1G usb stick, the led stays ON.  When using Lexar 1G
JumpDrive, the led always stays off (mounted and unmounted), and led only
blinks when it's being used actively (copy files to it, etc..)

  One can also unloads "ehci_hcd" and "uhci_hcd" to switch off the led, but
no other usb will work since these modules are used to control all usb
devices. :)

  One site mentions about sending start/stop SCSI cmd (1Bh) to flash drive
to turn off the led IF its handling is present in the firmware of the flash
drive. The cmds is in the LED section, Hut1_11.pdf (available in
I haven't try it yet, since sg_utils or sg3_utils doesn't exist in Grml

What is an "acs" cmd? 
The "% acs led blink | grep -ie led -ie blink" cmd in Grml Small return some
error messages "W: Couldn't stat source package ....". Probably the small
doesn't contain description messages.

Does anybody know where in kernel configuration file (if exist) that I need
to modify to change the kernel start date to be Jan 1 2000, instead of 1970?


--- Michael Prokop <mika at grml.org> wrote:

> * Andri Handoko <aphandoko at yahoo.com> [20070706 03:15]:
> >   I'm using the grml small 0.4. I created a hotplug event that
> automatically
> > copy files to the USB stick when it's plugin. The stick is Sandisk micro
> > cruzer 2G USB stick. Here is the dilema: I don't know when the copy will
> be
> > completed without looking at the monitor, and I'm planning not to use
> any
> > monitor. Is there a way to control the led; make it blinks every second
> when
> > files are being copy to the stick, and/or (the most importance part) to
> turn
> > OFF the led when the device is unmounted? (the "other" popular OS turns
> off
> > the led when the "Safely remove hardware" is selected). Can Grml do the
> same
> > action?
> Does manually loading the usbled kernel module help?
> If you want to trigger the *keyboard* LEDs on your own: there exist
> several tools:
> % acs led blink | grep -ie led -ie blink
> blinkd - Blinks keyboard LEDs e.g. for answering machine or fax
> ixbiff - notify user when mail arrives by blinking keyboard LEDs
> ledcontrol - scriptable keyboard led control
> ledcontrol-gtk - frontend for ledcontrol
> libparportled - manage an LED device plugged on a parallel port
> libparportled-dev - manage an LED device plugged on a parallel port -
> development files
> mailleds - Blink the keyboard-LEDs for incoming mail
> tleds - blinks keyboard LEDs for TX and RX network packets
> regards,
> -mika-

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