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-   -   Must unplug & replug hub to get flash drive recognized (https://www.linuxquestions.org/questions/linux-hardware-18/must-unplug-and-replug-hub-to-get-flash-drive-recognized-561635/)

MaxLinux 06-13-2007 09:59 PM

Must unplug & replug hub to get flash drive recognized
 
In your experience, are flash drives recognized when plugged into hubs (vs.
directly into a port on the computer)? By recognized I mean the LED on the
flash drive lights up, a Konqueror window opens showing the drive's contents,
and an icon appears on the desktop.

I have one system that will not recognize flash drives plugged into a
hub. Nothing happens! This was true with two different brands of USB 2 hubs
(Radio Shack Gigaware and D-Link). There are no flash drive recognition
problems when using these two hubs on a different system.

However, when using a third brand (Belkin), which happens to be USB 1, the
flash drive is recognized! Why? I would just use this Belkin except I also
have a DVD drive plugged into the hub, and USB 1 is too slow.

With the "non-working" hubs, I can get the flash drive recognized by
unplugging and re-plugging the hub's usb cable. I have to do this every time
I insert the flash drive.

All of the hubs mentioned are powered and connected to their AC adapters.

I was unable to find anything on Google about this. What comments do you have?
Is there anything I can do to get this working properly?

Thank you.

davimint 06-13-2007 11:20 PM

Not a expert but I think that the kernel sees the usb-hub as a single device much like a multicard-reader. When you un-plug & plug-in the hub when there is a device in the hub it's able to detect the hub and what is pluged into it. I have been reading a lot about this trying to get a better understanding of how events are generated with devices and what the kernel, udev, & hal are capable of doing.

Code:

I have one system that will not recognize flash drives plugged into a hub. Nothing happens!
Just curious is all the system's the same distribution of linux, because some distributions are not as current as others meaning that hal may be on one and not the other.

Anyway, hope this helps.

MaxLinux 06-26-2007 12:53 AM

An unexpected solution
 
Quote:

Originally Posted by MaxLinux
I have one system that will not recognize flash drives plugged into a
hub. Nothing happens! This was true with two different brands of USB 2 hubs
(Radio Shack Gigaware and D-Link). There are no flash drive recognition
problems when using these two hubs on a different system.

A surprising solution occurred tonight. Here in Greenville SC we had an intense thunderstorm and hail which knocked out the power. Shortly after I brought my system back up, I began to use the flash drive. Just as I was reaching for the hub's usb cable to unplug/replug it, up popped the flash drive in Konqueror!

Like many Linux systems, this one has been running for so long I can't remember when it was last booted. I have disconnected/reconnected the hub's ac adapter and usb cable many times, but it never entered my mind to try rebooting the computer itself. I would not have thought that rebooting would have any effect on this problem. So it took a power failure for me to discover this!

So everyone out there add "reboot the system" to your list of things to try if you have a funky behaving usb hub.


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