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Marginal USB ports
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Marginal USB ports

by dion.swamp.dk on Tue Sep 04, 2007 3:47 pm

I have an old'ish P4 machine which seems to have somewhat marginal USB ports, because some times the programmer will register and light the green LED and other times it will fail and this will show up in the system log:

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Sep  4 21:32:54 panther kernel: usb 1-1: new low speed USB device using uhci_hcd and address 11
Sep  4 21:32:54 panther kernel: usb 1-1: device descriptor read/all, error -71
Sep  4 21:32:55 panther kernel: usb 1-1: new low speed USB device using uhci_hcd and address 12
Sep  4 21:32:55 panther kernel: usb 1-1: device descriptor read/all, error -71
Sep  4 21:32:55 panther kernel: usb 1-1: new low speed USB device using uhci_hcd and address 13
Sep  4 21:32:55 panther kernel: usb 1-1: device descriptor read/8, error -71
Sep  4 21:32:55 panther kernel: usb 1-1: device descriptor read/8, error -71
Sep  4 21:32:55 panther kernel: usb 1-1: new low speed USB device using uhci_hcd and address 14
Sep  4 21:32:55 panther kernel: usb 1-1: device descriptor read/8, error -71
Sep  4 21:32:55 panther kernel: usb 1-1: device descriptor read/8, error -71


When using an extender cable (A-A) + the device cable (A-B) on one of the front ports of the machine I can get green LED to light up, but when I run avrdude -c usbtiny -p atmega88 I get:

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USB read error: expected 4, got -71
USB read error: expected 4, got -71
avrdude: initialization failed, rc=-1
         Double check connections and try again, or use -F to override
         this check.


It might be a good idea to add some code to explicitly ping the programmer and see if it's really there and output a clear error message which tells the user that the host is unable to talk to the programmer.

Every other USB device seems to work on this machine and the programmer also gives the shoddy error message that means that "the device is not there" when I hooked it up to my laptop, so it's not entirely broken.

Has anyone else seen the usbtiny code fail like this?

I'm inclined to blame my PC for this problem, after all, it's also the only machine that I've seen with broken serial ports.

I'll try getting a hub and see if that de-marginalizes my USB setup, in the mean time I guess this can serve as google fodder for the unfortunate owners of marginal hardware like mine.
dion.swamp.dk
 
Posts: 9
Joined: Sat Sep 01, 2007 5:53 pm
Location: Denmark

by adafruit on Tue Sep 04, 2007 4:54 pm

try using ehci or ohci instead of uhci

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by dion.swamp.dk on Wed Sep 05, 2007 2:00 am

ladyada wrote:try using ehci or ohci instead of uhci


I'm pretty sure my laptop has an ehci chip as it's very new and has USB 2 ports, so that's covered.

I just dug up an old pci card, which happens to be ohci and it looks like the usbtinyisp works perfectly on that.
dion.swamp.dk
 
Posts: 9
Joined: Sat Sep 01, 2007 5:53 pm
Location: Denmark

by adafruit on Wed Sep 05, 2007 2:12 am

so..its working for you now?

can you change it on your p4 too? i vageuely remember you could switch between uhci and ohci by swapping the modules but its been years.

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by dion.swamp.dk on Wed Sep 05, 2007 10:17 am

ladyada wrote:so..its working for you now?

can you change it on your p4 too? i vageuely remember you could switch between uhci and ohci by swapping the modules but its been years.


Forgive my lack of ESP, I really meant to say that the programmer worked perfectly on the laptop (ehci) and on the extra pci card (ohci).
dion.swamp.dk
 
Posts: 9
Joined: Sat Sep 01, 2007 5:53 pm
Location: Denmark

Please be positive and constructive with your questions and comments.