I'm running OpenWrt trunk (kernel 2.6.37) on a ramips router (Ralink RT3052 SoC). I'm using the DWC OTG USB driver from the Ralink SDK v3.3.0.0. I have numerous USB 3G modems (and USB flash drives) that all work perfectly with this router. However, I have one new modem, the Novatel Ovation MC547 (dual-carrier, 42 Mbps), that is unusable because it keeps disconnecting/resetting as soon as inserted:
usb 1-1: new high speed USB device using dwc_otg and address 2
scsi0 : usb-storage 1-1:1.0
hub 1-0:1.0: port 1 disabled by hub (EMI?), re-enabling...
usb 1-1: USB disconnect, address 2
usb 1-1: new high speed USB device using dwc_otg and address 3
scsi1 : usb-storage 1-1:1.0
hub 1-0:1.0: port 1 disabled by hub (EMI?), re-enabling...
usb 1-1: USB disconnect, address 3
usb 1-1: new high speed USB device using dwc_otg and address 4
scsi2 : usb-storage 1-1:1.0
hub 1-0:1.0: port 1 disabled by hub (EMI?), re-enabling...
usb 1-1: USB disconnect, address 4
usb 1-1: new high speed USB device using dwc_otg and address 5
scsi3 : usb-storage 1-1:1.0
hub 1-0:1.0: port 1 disabled by hub (EMI?), re-enabling...
usb 1-1: USB disconnect, address 5
usb 1-1: new high speed USB device using dwc_otg and address 6
scsi4 : usb-storage 1-1:1.0
hub 1-0:1.0: port 1 disabled by hub (EMI?), re-enabling...
usb 1-1: USB disconnect, address 6This modem is supported by the Option serial driver in recent kernels. It works fine in my Linux PC (Fedora 13) and my Windows 7 laptop. It also works in my Fonera 2.0n router (another Ralink RT3052 board).
I have tried everything I can think of to solve this problem, including updating the drivers and experimenting with drivers/usb/core/quirks.c.
Interestingly enough, it doesn't reset when connected to the problem router via an external, non-powered USB hub. The modem switches (via usb_modeswitch) and the serial ports are exposed... but they don't work 
I'm all out of ideas here. I'm concerned it may be a hardware problem with the router's USB host (possibly an inrush current issue)... but it works fine with all other devices I can throw at it. I'm hoping it can be resolved by driver fixes or configuration, etc.
Any help and/or suggestions are greatly appreciated.
Regards,
Layne