This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

USB EHCI high power consumption in suspend.

Other Parts Discussed in Thread: DM3730, TUSB1210

Hi,

I'm fine tuning power management for TI DM3730 with Android 2.3.4 kernel 2.6.37.

The USB-EHCI hub connects to a Phy (TUSB1210) is  plugged with a Sierra 3G module.

We found:

case 1:

When it goes to suspend,the USB-EHCI clock output is off. But we still can't gain enough power saving, For example it still takes A mA

case 2:

Then I remove "usb_ehci_init(&ehci_pdata);" in board-config files, the USB device is complete not loaded when it boots. It takes B mA.

Conclusion:

A-B is around 25mA.

It means even we disable ULPI clock output when it goes to suspend, the USB-EHCI Root Hub still consume 25mA.

Any ideas to reduce this 25mA consumption in suspend mode ??