Brightness of HDD status LEDs is cycling from 0% to 100% back to 0% continuously

[djurny]

Hi,

Not sure if anyone has seen the same as I have been seen on my box; the HDD status LEDs are cycling in brightness, from 0% to 100% and back to 0% continuously. It's a smooth transition, no flashy circus.

I might have triggered this myself, but no idea how? Is this is a new feature? I tried to make some video of it, but it is quite difficult to see.

Groetjes,

[gprovost]

Did you put your HDD in sleep mode ?

[djurny]

Hi,

Only the USB HDD (sdc) is configured to have spindown after some minutes, the others were not explicitly configured to enter either standby/sleep mode. Note that all of the HDD status LEDs show are cycling, not just a few.

 

hdparm shows the following strange values:

 

Device:	Used as:	Interface:	Media:	hdparm -C says:
sdb	rootfs	USB	USB stick	drive state is:  standby
sdg	swap	SATA	SSD	drive state is:  active/idle
sda	data0	SATA	HDD	drive state is:  active/idle
sdd	data1	SATA	HDD	drive state is:  active/idle
sde	data2	SATA	HDD	drive state is:  active/idle
sdf	data3	SATA	HDD	drive state is:  active/idle
sdc	parity0	USB	HDD	drive state is:  active/idle

 

I've never heard that a USB media stick can be put in standby mode? Even more strange is that '/' is running off of this USB device.

 

See below for more details.

 

Spoiler

 

AHCI link power modes are as follows:

root@kobol0:~# egrep . /sys/class/scsi_host/*/link_power_management_policy
/sys/class/scsi_host/host0/link_power_management_policy: med_power_with_dipm
/sys/class/scsi_host/host1/link_power_management_policy: med_power_with_dipm
/sys/class/scsi_host/host2/link_power_management_policy: med_power_with_dipm
/sys/class/scsi_host/host3/link_power_management_policy: med_power_with_dipm
/sys/class/scsi_host/host4/link_power_management_policy: med_power_with_dipm

 

USB stuff (whitespace added and fluff removed):

root@kobol0:~# lsusb -t
/:  Bus 02.Port 1: Dev 1, Class=root_hub, Driver=xhci-hcd/1p, 5000M
    |__ Port 1: Dev 2, If 0, Class=Hub, Driver=hub/4p, 5000M
        |__ Port 1: Dev 3, If 0, Class=Mass Storage, Driver=usb-storage, 5000M
        |__ Port 2: Dev 4, If 0, Class=Mass Storage, Driver=usb-storage, 5000M
        |__ Port 4: Dev 5, If 0, Class=Vendor Specific Class, Driver=r8152, 5000M


root@kobol0:~# egrep . /sys/bus/usb/devices/*/power/control
/sys/bus/usb/devices/2-1/power/control:   auto
/sys/bus/usb/devices/2-1.1/power/control: auto
/sys/bus/usb/devices/2-1.2/power/control: auto
/sys/bus/usb/devices/2-1.4/power/control: auto
/sys/bus/usb/devices/usb1/power/control:  auto
/sys/bus/usb/devices/usb2/power/control:  auto

root@kobol0:~# lsusb
Bus 002 Device 003: ID 0781:5583 SanDisk Corp. Ultra Fit

 

 

 

Groetjes,

[gprovost]

Are all the HDD status LED (blue) doing this dimming in and out simultaneously ?

[djurny]

Just now, gprovost said:

Are all the HDD status LED (blue) doing this dimming in and out simultaneously ?

Hi @gprovost, replies have crossed.

Yes, all the HDD status LEDs are cycling simultaneously. For the HDD with activity, it's still blinking with activity. I cannot make out if the actitivy LED itself is also cycling, my eyes are a bit too old for that.

Groetjes,

[gprovost]

Sorry a bit confused. Can you confirm again clearly your statement.

 

On 11/30/2020 at 3:21 PM, djurny said:

I cannot make out if the actitivy LED itself is also cycling, my eyes are a bit too old for that.

 

Only the HDD activity LED are impacted by the dimming cycling ? Or the System Activity LED is also impacted ?

 

[djurny]

Hi,

It's only the "HDD x Activity LEDs" that are cycling. The other LEDs are not showing this cycling. 

The cycling speed appears to increase with CPU frequency, just like how the "System Activity LED" (heartbeat trigger) frequency will increase when CPU frequency increases.

I made a video of the effect, but have some trouble uploading it (>20MiB). here: https://streamable.com/v8wa36,

 

Note I do not have any trouble with this effect, just wondering if this is by design and how I can customize it :-)

 

Groetjes,

 

Edited December 1, 2020 by djurny

[gprovost]

Thanks for the video.

 

It's the SATA controller which is doing that dimming thingy

 

Effectively when I configure link_power_management_policy to med_power_with_dipm I will see the LED dimming cycle happen.

By default link power policy is max_performance

 

root@helios64:/sys/class# egrep . /sys/class/scsi_host/host*/link_power_management_policy
/sys/class/scsi_host/host0/link_power_management_policy:max_performance
/sys/class/scsi_host/host1/link_power_management_policy:max_performance
/sys/class/scsi_host/host2/link_power_management_policy:max_performance
/sys/class/scsi_host/host3/link_power_management_policy:max_performance
/sys/class/scsi_host/host4/link_power_management_policy:max_performance

 

Did you set med_power_with_dipm yourself. If not I wonder what program did that for you.

 

For now i don't see the point to use a different link_power_management_policy than max_performance. But that deserves some investigation.

 

[djurny]

Hi @gprovost,

Looks like I had 'tlp' installed, presumably during some messing about with getting things like powertop installed. Thanks for the trigger: Removed tlp and LEDs are back to normal!

Groetjes,

[ebin-dev]

So the HDD LEDs are really dimmed as shown in the video linked above by @djurny.

Does that mean that there is in fact a way to dim the LEDs contrary to what is stated in the other thread ?

[gprovost]

@ebin-dev No unfortunately it is not a way to dim the LED ;-)