> I went into the driver, and came to know that this hub was returning (1011
> 0010) as wHubCharacteristics, and pPwrOn2PwrGood as 0. This hub is a powered
> hub (doesn't draw power from bus), and high speed. I only use all high
> speed, so I guess TT's do not come into picture.
Lack of power switching implies that the hub follows the USB 1.0 standard, but since it is high speed it actually follows the USB 2.0 standard. Also, overcurrent protection may be omitted only for bus-powered hubs. Clearly the value is wrong.
Is power switching a must for USB 2.0? I'm confused here.
> The driver used to recognize only the hub - nothing else behind it. So, I
> changed the wHubCharacteristics with a proper value whenever I found this
> device (for a temporary fix). Now, I can see behind this hub.
Do you mean that after your changes, the 2.6.10 USB core is able to detect devices plugged into the hub? What change did you make to wHubCharacteristics?
What I did was, I modified the wHubCharacteristics that was read from the device to a value that I constructed after reading the specs (1010 1001). How exactly is this value obtained from the device? I know it's not stored in the device. Is it related to the problems with the power supply to the board?
> But, I am getting a few (very infrequent) "port x disabled by hub (EMI?),
> re-enabling.." messages. I didn't get much information in the code/specs
> about the reason.
That message is printed whenever a hub disables one of its ports all by itself. This can happen because of electromagnetic interference, or a bad cable or connector, or because the device plugged into the port is malfunctioning, or because the hub itself is malfunctioning.
Alan Stern
Thanks!
_________________________________________________________________
FREE pop-up blocking with the new MSN Toolbar – get it now! http://toolbar.msn.click-url.com/go/onm00200415ave/direct/01/
------------------------------------------------------- SF email is sponsored by - The IT Product Guide Read honest & candid reviews on hundreds of IT Products from real users. Discover which products truly live up to the hype. Start reading now. http://ads.osdn.com/?ad_id=6595&alloc_id=14396&op=click _______________________________________________ Linux-usb-users@lists.sourceforge.net To unsubscribe, use the last form field at: https://lists.sourceforge.net/lists/listinfo/linux-usb-users
