I recently had a problem with the USB host mode not working on my N800 and just wanted to share the solution in case it may help out someone having the same problem.
The problem: Having followed the simple steps to set the usb to host mode manually, it would not recognize any devices and there were minimal activity on dmesg.
Troubleshooting:
1. Clearing dmesg and checking the status of the USB port.
Nokia-N800-36-5:~# dmesg -c
Nokia-N800-36-5:~# more /sys/devices/platform/musb_hdrc/mode
b_idle
[12886.257812] menelaus 1-0072: Setting voltage 'VMMC' to 3000 mV (reg 0x0a, val 0xb8)
[12886.890625] menelaus 1-0072: Setting voltage 'VDCDC3' to 2800 mV (reg 0x07, val 0x29)
[12892.070312] menelaus 1-0072: Setting voltage 'VDCDC3' to 2800 mV (reg 0x07, val 0x29)
[12892.875000] menelaus 1-0072: Setting voltage 'VMMC' to 3000 mV (reg 0x0a, val 0xb8)
but still no reaction when plugging in devices.
5. Setting the mode back to peripheral and doing it all over:
* It did keep its mode trough the boot, but to no avail.
7. I then realized there is a third mode "otg" which supposedly is the default... Tried the whole process up and down between the modes without success.
The solution: At this point I decided I will reset it back to the original, do more research, and come back later. As I understood "otg" was the default mode for the device I chose to set it to that and restart.
Pretty much the same as last, just with a minuscule difference. The prcm, whatever that means, had changed from reading 00000500 to 00a80500.
But two second after I got a message on the screen: "USB device not supported." (but I expected that and it actually means it works )
So restarting the device with USB in OTG mode obviously did the trick. I'm not gonna theorize too much because Linux is not my cup of tea... but seems some extra devices was found under boot for which the device links/files had not been created before.
I recently had a problem with the USB host mode not working on my N800 and just wanted to share the solution in case it may help out someone having the same problem.
The problem: Having followed the simple steps to set the usb to host mode manually, it would not recognize any devices and there were minimal activity on dmesg.
Troubleshooting:
1. Clearing dmesg and checking the status of the USB port.
3. Plug in keyboard, mouse, memory stick, but..
4. Trying some more...
5. Setting the mode back to peripheral and doing it all over:
6. Having switched back and forward several times between modes "peripheral" and "host" I decided to try setting it to "host" and restart the device.
7. I then realized there is a third mode "otg" which supposedly is the default... Tried the whole process up and down between the modes without success.
The solution: At this point I decided I will reset it back to the original, do more research, and come back later. As I understood "otg" was the default mode for the device I chose to set it to that and restart.
But two second after I got a message on the screen: "USB device not supported." (but I expected that and it actually means it works )
So restarting the device with USB in OTG mode obviously did the trick. I'm not gonna theorize too much because Linux is not my cup of tea... but seems some extra devices was found under boot for which the device links/files had not been created before.
OK, hope that may help anyone.
Cheers