[Tfug] USB hang

[Zack Breckenridge]

Actually, I failed to answer to question of whether a USB device can wreck
a system, because I don't know. I can tell you that power over USB was
never intended to be used the way it is today - it's become standard, but
that's because so many USB devices were pulling more power than the specs
"allowed." It was possible, so hardware designers just did it (you know,
like making USB powered battery chargers and lamps - USB was not originally
made for this purpose). So even though I can't answer you positively on
that, I'd say It's probable.

However, it being USB 2.0 does not guarantee its being supported by the
Linux kernel, even the latest kernel. That depends on a couple factors:

- did the manufacturer of the USB device contribute drivers for the Linux
kernel, or just Windows?

- if not, did they release the specs for the device?

- if they did release specs, was a driver written by a Linux developer, and
when?

That's why I asked for uname output and dmesg output, because I can
probably take a look at the kernel source for you and tell you if a driver
was available at that time, amongst other things.

Its sounds like all the hardware worked just find with Myth before
something failed, so obviously drivers became available at some point.

Hope I can help with your problem!

Zack
On Aug 7, 2012 5:47 PM, "erich" <erich1 at copper.net> wrote:

> I know,
>           I can't test the "bad hard drive" theory because this is the
> only SATA machine
> that I have. One would like to drop the drive into another SATA machine
> and see
> what happens.
>           At this point I can answer only one of your questions: Mythdora
> 12.
>
> Sounds like the answer is "no".  A USB device can't wreck a USB system.
>
>
>                                                               Erich
>
> PS: It's USB 2.0, and this Knoppix can handle it.
>
>
>                                                               EWF
>
> Zack Breckenridge wrote:
>
>>
>> Erich,
>>
>> Hi my name is Zack. Long time free Unix user, and Tucson resident, new to
>> this list.
>>
>> From your description, it sounds like the SATA disk may be dead. Usual
>> hard disk failure... Also, it also sounds like the version of Knoppix
>> you're booting from might have an old kernel that doesn't support either
>> your USB controller (properly anyway), or your Network card or both. So 3
>> questions:
>>
>> 1) what version of MythTV was this?
>> 2) what is the output of "uname -a" in your Knoppix?
>> 3) can you provide "dmesg" output (from the newest live CD you can get
>> your hands on)?
>>
>> Thanks!
>>
>> Zack Breckenridge
>>
>> On Aug 7, 2012 4:17 PM, "erich" <erich1 at copper.net <mailto:
>> erich1 at copper.net>> wrote:
>>
>>     OK,
>>            I have a DVR system that runs MythTV. I also use it to
>>     watch internet news clips with
>>     a browser and look at various forms of entertainment with an
>>     external USB hard drive.
>>             The other day the system froze: moving the mouse got no
>>     response. The keyboard
>>     froze. I had to shut it down by holding the power button in.
>>
>>              It's in my shop now. It won't boot from the SATA drive,
>>     but Knoppix will boot.
>>     First I thought I was a victim of a lightning strike, but there is
>>     no evidence. The
>>     TV antenna works fine. The LAN works fine.
>>
>>             Here are the facts:
>>                            1)  I cant get the network interface to
>>     run: I type ifconfig and
>>                                  eth0  is not present.
>>
>>                            2) Knoppix detects the USB ports, but when
>>     I plug any USB
>>                                 device into any port the system
>>     freezes, (I tried a thumb drive
>>                                 and a USB mouse)
>>
>>                            3) A USB hard drive was plugged into it at
>>     moment of freeze.
>>                                 I checked it on another system, and my
>>     hard drive is OK,
>>                                 and my other system is OK. (Yes this
>>     took a lot of nerve.
>>                                 Bugs can be contagious.)
>>
>>               My first question is can a faulty USB device damage a
>>     USB system? (I don't
>>     have the nerve to plug the USB mouse into any other system)
>>
>>               My 2nd question is can there be some kind of short? The
>>     case has vent holes
>>     on top and debris may fall in.
>>
>>
>>
>>                                                          Cheers,
>>
>>                                                          Erich
>>
>>
>>
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>
>
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