USB scanner detected but later not found.

rnturn · 06-23-2016, 10:38 AM

Sorry if that Subject: line is cryptic...

I'm running an up-to-date-with-patches OpenSUSE 13.2 and occasionally have a situation where my Epson Perfection 2400 Photo scanner stops being detected when I run The GIMP and attempt to scan something. I've tried 'lsusb' and 'sane-find-scanner' which both return information that shows that the scanner has been detected on "Bus 003" as "Device 004". However, when trying to scan a document, following the "Create -> Xsane: Device dialog..." route in The GIMP shows the "scanning for devices" window for about 30 seconds and then tells me that no scanner was found. Unplugging and re-plugging in the scanner fixes the problem. [Edit: Unplugging/replugging from the USB bus; not power cycling the scanner.] Once that's been done, the scanner will be detected for a day or so but will mysteriously be undetected again if I haven't scanned anything for a day or so (yeah, the system is not routinely shut down).

Anyone else run into this? Ever figure out what's causing it?

TIA...

--
Rick

jailbait · 06-23-2016, 11:21 AM

One possible cause for this problem is fluctuating power on the USB port. Do you sometimes use other devices on a USB port? Do you use a USB hub? Is your computer power supply nearly maxed out to where you have the occasional "brown out" within the computer?

--------------------
Steve Stites

michaelk · 06-23-2016, 12:22 PM

I suspect the scanner is going into standby mode either due to the computer going to sleep or it might have a built in timer. Western Digital USB drives awhile back, if I remember correctly would automatically go into standby and Windows but not linux was able wake them back up. You could disable the standby mode but that was a drive command function and would not know how to fix the scanner unless there was some setting in /proc.

rnturn · 06-23-2016, 02:17 PM

Quote:

Originally Posted by jailbait

One possible cause for this problem is fluctuating power on the USB port. Do you sometimes use other devices on a USB port?

The scanner is plugged into a USB port on the motherboard. Nothing that is plugged into the m'board ports is powered only by the USB; separate power warts for everything.

Quote:

Do you use a USB hub?

Yes. Powered hub plugged into one of the m'board USB ports. As noted above, scanner is plugged into m'board port. On this hub, I do have non-separately powered devices that are used on this bus like SD/CF cards from cameras and the occasional smartphone connection.

Quote:

Is your computer power supply nearly maxed out to where you have the occasional "brown out" within the computer?

Hard to tell that. The system is housed in a full-tower case with dual power supplies: one for m'board+boards in the PCI/AGP slots and a second for disks.

ferrari · 06-23-2016, 09:23 PM

This could be due to USB autosuspend (power management) at play perhaps?

This wiki reference might be helpful
https://wiki.archlinux.org/index.php...SB_autosuspend

It can be disabled globally by configuring usbcore at boot via a config file in /etc/modprobe.d/ eg /etc/modprobe.d/30-disable-usb-autosusend.conf

Code:

options usbcore autosuspend=-1

It will take effect next boot. see if that helps.

ferrari · 06-23-2016, 09:35 PM

BTW, as Michael already hinted at, it could just be the scanner's sleep mode function doing what it's supposed to do

Epson Perfection 2400 Photo FAQ

Quote:

The scanner has a power saving function (sleep mode); press the Start button to "wake" the scanner. Or unplug the USB cable or power cable, then plug it back in. If you are using the transparency unit, make sure it is plugged into the back of the scanner. Make sure the power cord is connected to the scanner and plugged into a power outlet.

AwesomeMachine · 06-23-2016, 11:42 PM

I have seen where the order the devices are plugged into the hub will cause one to fail. I have a pvrusb2 device that if it isn't in the first slot, or if anything is plugged in before it, my printer isn't detected after a few minutes. It's a module bug.

rnturn · 06-30-2016, 10:33 AM

Quote:

Originally Posted by ferrari

This could be due to USB autosuspend (power management) at play perhaps?

Code:

options usbcore autosuspend=-1

It will take effect next boot. see if that helps.

Worth a try.

Oddly, the scanner sometimes goes missing sometimes several times a day though lately I've been scanning something about every other day without needing to un/re-plug the USB cable.

Still working this one... Thanks for the pointer.

--
Rick

rnturn · 06-30-2016, 10:37 AM

Quote:

Originally Posted by ferrari

BTW, as Michael already hinted at, it could just be the scanner's sleep mode function doing what it's supposed to do

Epson Perfection 2400 Photo FAQ

If that's the case, it keep odd hours. I find it odd that it can happen several times on one day while other times I can scan something -- like today for example -- wit no problem after not having done scanning for a couple of day. It's rather random. Makes it an, um, interesting problem.

--
Rick

ferrari · 06-30-2016, 01:57 PM

Quote:

If that's the case, it keep odd hours. I find it odd that it can happen several times on one day while other times I can scan something -- like today for example -- wit no problem after not having done scanning for a couple of day. It's rather random. Makes it an, um, interesting problem.

--
Rick

Well, does pressing the 'Sart' button awaken the device again when needed?

Otherwise, let us know how disabling the autosuspend (of USB ports) works.