Hi, Linux USB community
Recently I brought a USB sound card, everything looks fine except sometime
this thing happen:
[ 2870.009042] hub 1-0:1.0: port 1 disabled by hub (EMI?), re-enabling...
[ 2870.009051] usb 1-1: USB disconnect, address 3
[ 2870.372015] usb 1-1: new full speed USB device using uhci_hcd and address 4
[ 2870.693906] usb 1-1: configuration #1 chosen from 1 choice
[ 2870.759002] input: Burr-Brown from TI USB Audio CODEC as
/devices/pci0000:00/0000:00:1a.0/usb1/1-1/1-1:1.3/input/input8
[ 2870.784180] input,hidraw0: USB HID v1.00 Device [Burr-Brown from TI
USB Audio CODEC ] on usb-0000:00:1a.0-1
Everytime this happened during my listening. And after this, I have to reset
my application to make sound work again.
Kernel is 2.6.27-11, which is distribute with Kubuntu. I checked the code of
upstream, found this:
> /*
> * EM interference sometimes causes badly
> * shielded USB devices to be shutdown by
> * the hub, this hack enables them again.
> * Works at least with mouse driver.
> */
> if (!(portstatus & USB_PORT_STAT_ENABLE)
> && !connect_change
> && hdev->children[i-1]) {
> dev_err (hub_dev,
> "port %i "
> "disabled by hub (EMI?), "
> "re-enabling...\n",
> i);
> connect_change = 1;
> }
I don't understand the comment here. So I checked the git-annonate, but seems
this one had been added since the git repository created.
Is there anybody can elaborate the comment(google didn't help me on this so
far...), and if it due to some bad hardware design/programming? And what's
wrong indeed?
Thanks very much!
--
regards
Yang, Sheng
--
To unsubscribe from this list: send the line "unsubscribe linux-usb" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
