On Wed, Jun 20, 2012 at 05:38:44PM -0500, Donald Kayser wrote: > Hello, > > I develop linux drivers for an embedded system with USB devices. The > USB drivers in question have been stable for a while, at least since > linux 2.6.26.n. Nice. Any reason why they aren't in the main kernel.org tree? > We have to move the system to the newest 2.6 kernel > (2.6.39.4) that has support for video hardware. When I built the > embedded system's USB drivers for the 2.6.39.4 kernel, I keep > getting the error message "Resource Temporarily Unavailable" when > attempting to 'cat' the device file. No error message appear in the > syslog. My USB driver uses the same kind of calls as usb-skeleton.c > to create the device file via usb_register() in the init function > and usb_register_dev() in the probe callback. The device is create > with a dynamic minor number in its name in /dev as expected. But > every use of this file comes back with the error. My debug printk > indicate my open function is not ever being called. Can you run 'git bisect' to track down the offending patch? 2.6.39 was years ago, I can't remember what happened in the kernel tree one month ago... > I checked the difference between usb-skeleton.c files and there has > only been an addition of adding a llseek entry in the file > operations structure. I modified my driver and it didn't make a > difference - long shot. I wouldn't trust the usb-skeleton.c to have been kept up to date. > I tested kernels 2.6.39.4, 2.6.38.8, 2.6.37.7, 2.6.37.1, 2.6.36.4. > It works in kernels before and including 2.6.36.4. It stops working > for all kernels tested beyond and including 2.6.37.1. That gives you a good start to run 'git bisect' on. thanks, greg k-h -- 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
