[quoted lines by Greg KH on 2012/04/05 at 18:19 -0700] >Then that is up to those other platforms. No, it isn't. Users need this software to work, even if other platforms haven't gotten around to providing all of the generic stuff yet. Also, it's a lot more trouble for us, in terms of development, maintenance, and verification, to have to support a vast layer of stuff in a platform-dependent way when supporting basic USB operations is really all that needs to be platform-dependent. Now I'm sure you're wondering what software we're discussing. We maintain software that controls braille devices. We're talking about giving blind people access to all possible environments. A braille device is as important to a blind person as your monitor is to you. Yes, we may do things in ways which don't exactly fit your idealistic way of looking at things, but that's because we're doing our level best to open up areas of access to blind people which have, to date, been denied to them - e.g. the grub boot prompt. Now I'm still hoping that you, or someone else, might be kind enbough to answer my question instead of just deciding that I'm too stupid to just do it the right way. >And the /dev path is quite predictable, look at /dev/serial/ and use the >symlinks there that are provided for you. I don't have /dev/serial. Maybe it's relatively new. >Unless your device is "dumb" and doesn't have a serial number, then you >might have problems, but you can work around them by looking at physical >positions and the like. There are a lot of different types of braille devices. Some have good USB definitions and others don't. Since we aren't in the business of promoting one model over another, since each user really ought to get the device which best meets his own personal needs, we need to design for the worst case. >I totally fail to see how this pertains to Linux, given that we already >support this device just fine, I asked about how to do it with USBFS for two reasons. One is that I use our USBFS implementation for development and testing. The other is that users of this mailing list understand Linux, USBFS, etc. In other words, I asked specifically about how to do it on Linux using USBFS because it's something we all udnerstand. In the end, of course, what we implement will work on many more platforms than just Linux, but it'll be implemented in common, portable code. >and you shouldn't be writing userspace serial tty drivers anyway, as no one >will be able to access the device that way (unless you are going to emulate >the whole POSIX serial port api from userspace as well, and surely you >wouldn't do that...) Maybe, in the opinion of an idealist, I shouldn't, but, yes, we do it sort of in that way. It's simply a necessity when one wants 99%+ of the code to be common but has the need to support any arbitrary platform. The way we've done it has ended up being quite simple and is a relatively small amount of code. On Unix systems, for example, we still do use termios underneath for real serial devices, and have just a small set of tiny stubs for USB to serial adapters. -- 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 End of Salvation. EMail: dave@xxxxxxxxx | Canada K2A 1H7 | http://Mielke.cc/now.html 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
