On Tue, Jan 31, 2012 at 02:03:51PM +0200, Felipe Balbi wrote: > debugfs APIs will return two different error > values depending on the situation: > > -> if debugfs isn't enabled in the kernel: > it will return -ENODEV > > -> if debugfs is enabled in the kernel: > it will return NULL > > This means that blindly using IS_ERR() isn't > enough and, in fact, will not work on a real > error condition. > > While we could be checking for a NULL pointer > only because we only compile and link debugfs.o > when CONFIG_DEBUG_FS is enabled, we decided > to play it safe should any of the debugfs rules > change over time. The rules should not change over time, and if they do, any in-kernel users will be fixed up. This shouldn't be that hard, just check for NULL and move on if an error happens, don't mess with the IS_ERR() stuff at all. Look at how the USB core handles this, and use that logic. 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
