I'm using usbfs to support braille devices. I'm experiencing a problem with one such device that I've never encountered before. When the device is opened for the first time (after connecting the USB cable), it works fine. All operations succeed as expected. When the device is closed and reopened, however, it no longer responds (for example, to "get descriptor" requests), i.e. the ioctl()s yield timeouts. Disconnecting/reconnecting the USB cable restores normal operation, but only for one open. I know this problem has nothing to do with faulty support of autosuspend because I've made sure that feature was disabled via writing "on" to "power/level" and by writing "-1" to "power/autosuspend". One unusual thing I'm noticing is that the "release interface" which is done just before the close of the device takes about five seconds to complete. From strace: 08:59:17.106788 ioctl(10, USBDEVFS_RELEASEINTERFACE, 0xbfe8a58c) = 0 <5.001493> 08:59:22.108524 close(10) = 0 <0.000032> The vendor assures me that reopening (without disconnect/reconect) the device does work on Windows. Can any of you think of any possibilities that I should check? Is there any way I can get the kernel to log all of the low-level USB operations involving the device? -- Dave Mielke | 2213 Fox Crescent | The Bible is the very Word of God. Phone: 1-613-726-0014 | Ottawa, Ontario | 2011 May 21 is the Day of Judgement. EMail: dave@xxxxxxxxx | Canada K2A 1H7 | 2011 Oct 21 is the End of the World. http://FamilyRadio.com/ | http://Mielke.cc/bible/ -- 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
