my setup :

Ubuntu 14.04 LTS dual boot with windows 7.

uname -a : Linux nikhil 4.2.0-42-generic #49~14.04.1-Ubuntu SMP Wed Jun 29 20:22:11 UTC 2016 x86_64 x86_64 x86_64 GNU/Linux

usb devices :

lsusb :
Bus 002 Device 002: ID 8087:0024 Intel Corp. Integrated Rate Matching Hub
Bus 002 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 001 Device 004: ID 1c4f:0002 SiGma Micro Keyboard TRACER Gamma Ivory
Bus 001 Device 003: ID 046d:c05a Logitech, Inc. M90/M100 Optical Mouse
Bus 001 Device 002: ID 8087:0024 Intel Corp. Integrated Rate Matching Hub
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
What I am doing : trying to understand UART driver in kernel and want to write a custom one.

Problem: I have a beaglebone black board, connected via a usb cable to power it up, one usb to uart cable. One day back it was working well and I was able to get uart prints via /dev/ttyUSB0 port. Today if I connect all of this setup I am getting this error in dmesg

[ 137.719417] usb 2-1.2: new full-speed USB device number 3 using ehci-pci
[ 137.791482] usb 2-1.2: device descriptor read/64, error -32
[ 137.967627] usb 2-1.2: device descriptor read/64, error -32
[ 138.143778] usb 2-1.2: new full-speed USB device number 4 using ehci-pci
[ 138.215838] usb 2-1.2: device descriptor read/64, error -32
[ 138.391989] usb 2-1.2: device descriptor read/64, error -32
[ 138.568138] usb 2-1.2: new full-speed USB device number 5 using ehci-pci
[ 138.976482] usb 2-1.2: device not accepting address 5, error -32
[ 139.048602] usb 2-1.2: new full-speed USB device number 6 using ehci-pci
[ 139.456902] usb 2-1.2: device not accepting address 6, error -32
[ 139.456999] usb 2-1-port2: unable to enumerate USB device
[ 357.890716] usb 1-1.2: new high-speed USB device number 5 using ehci-pci
[ 358.180986] usb 1-1.2: unable to read config index 0 descriptor/start: -71
[ 358.180992] usb 1-1.2: can't read configurations, error -71
[ 670.985054] usb 1-1.2: new high-speed USB device number 7 using ehci-pci
[ 671.275398] usb 1-1.2: unable to read config index 0 descriptor/start: -71
[ 671.275404] usb 1-1.2: can't read configurations, error -71


Somewhere on internet it was mentioned that error -32 is a usb power problem. Also I came to know that while enumerating the device, host sends read write packets and to allocate an address, that are seen as failed in dmesg.

Is there any solution for it, or my hardware has failed? If failed which one is most likely to be corrupted, beaglebone black board or usb cable?

You may have a hardware failure... But most motherboards have multiple USB controllers - try one of the others if you can.

NOTE: It is possible your cable (or the device attached) may be drawing too much current that may cause the damage. Hard to tell from the outside.

1 members found this post helpful.

I changed my usb to uart cable and its working fine.
I didn' figured why the previous cable wasn't working though.