TUSB8041: Port disable/power down

Hanyu Li

Part Number: TUSB8041

Tool/software:

Hi,

I am trying to use libusb library to control hub port power on a linux system. The power on port is closed after I called the following code:

#define USB_PORT_FEAT_POWER = (1 << 3)

#define USB_CTRL_GET_TIMEOUT = 500

libusb_control_transfer(m_deviceHandle,

LIBUSB_REQUEST_TYPE_CLASS | LIBUSB_RECIPIENT_OTHER,

LIBUSB_REQUEST_CLEAR_FEATURE,

USB_PORT_FEAT_POWER,

portIndexOnHub,

nullptr,

USB_CTRL_GET_TIMEOUT);

But I can still watch it by using linux command "lsusb", even though the usb device has been unplugged.

It seems that hub not to report port correct status to the host.

Is this a correct phenomenon? or if I need to do extra config to receive the change message?

Thanks

hanyu

10 months ago

0 Brian Zhou 10 months ago

TI__Guru*** 146785 points

The easy way to control ports is to control internal register, but it has to be TUSB8041A device.

Regards

Brian

0 Hanyu Li 10 months ago in reply to Brian Zhou

Prodigy 10 points

Thanks for your responding, Our product has been selected as TUSB8041. I just want to temporarily power off a port, not permanently disable it. Therefore I chose the way described before so that I can turn it back on if needed without affecting other USB communications on this hub. I tested the libusb_control_transfer() method, it only disconnected the power, but did not let Linux know that the USB has been disconnected. Is there any other way to achieve this? Or what additional configuration do I need to do?

Regards

hanyu

0 Brian Zhou 10 months ago in reply to Hanyu Li

TI__Guru*** 146785 points

Hi Hanyu:

From port feature, there is no option to disable or enable downstream ports with USB command . So there is no other way to disconnect a port and let Linux know.

Best

Brian

0 Hanyu Li 10 months ago in reply to Brian Zhou

Prodigy 10 points

I got it, thank you very much.

Regards

hanyu

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TUSB8041: Port disable/power down