On Thursday 19 May 2005 9:22 pm, [EMAIL PROTECTED] wrote: > From: David Brownell [mailto:[EMAIL PROTECTED] > Sent: Thursday, May 19, 2005 10:25 AM > To: Borse, Ganesh > > > how is it shown in sysfs? In any file? > > >>The current device configuration is bConfigurationValue, > >>matching the USB spec. > > No, bConfigurationValue does not give any information about overcurrent > condition. It shows whether device (the hub) is configured (value 1) or > not (value 0).
Go back and re-read what I said. I didn't say that was found there, I said it showed the configuration number (e.g. #1). All to support figuring out the the power budget. > Also, file power/state does not contain this information. Ditto. In fact I said to see how "lsusb" asks the hub driver for port status: > After going through USB2.0 Specs pdf, I came to know that GetPortStatus > request provides an information for overcurrent (in the form a bit set > to 0 or 1). This is explained in Tables 11-19 and 11-21 of USB2.0 specs. > > Accordingly, I created a test program and executed it on the bus powered > 4-port external hub having bus powered devices on all 4 ports. > All the time I got the wPortStatus value of 259 (from GetPortStatus > IOCTL o/p). > 259-decimal means bits 0, 1, and 8 are set. According to Table 11-21, > bits 0, 1 signify that device is connected and port enabled. Bit 8 > states that the given port is not in powered-off state. The bit 3 - > PORT_OVER_CURRENT bit was never set. Like I said: see how "lsusb" does it. It actually decodes the bits. > Why is this not reported on Port Status field, wPortStatus? > Is this the limitation of Linux USB drivers? There is no wPortStatus value in sysfs. Nor IMO should there be. > Windows correctly displays this information with pop-ups and alerts > users about this. And "lsusb" correctly displays the information, as I pointed out. Didn't you say _you_ were going do some wizzy X11 thing on Linux? > Also provides way of troubleshooting this condition by > recommending moving devices to other ports. Please consider re-reading what I wrote in the first place. Including the part about what the messages you saw actually meant... ------------------------------------------------------- This SF.Net email is sponsored by Oracle Space Sweepstakes Want to be the first software developer in space? Enter now for the Oracle Space Sweepstakes! http://ads.osdn.com/?ad_id=7412&alloc_id=16344&op=click _______________________________________________ linux-usb-devel@lists.sourceforge.net To unsubscribe, use the last form field at: https://lists.sourceforge.net/lists/listinfo/linux-usb-devel
