On Sun, Mar 04, 2007 at 03:42:25PM -0500, Robin Getz wrote: > On Sun 4 Mar 2007 14:46, Russell King pondered: > > On Thu, Mar 01, 2007 at 07:03:02PM -0500, Mike Frysinger wrote: > > > the console= bootcmd allows for controlling of the initial state of > > > flow control by adding/omitting the 'r' suffix ... > > > > The console command *only* sets the state for the kernel's use of one > > serial port. It does not affect any other serial port, so tying > > random RTS behaviours into that command line option is absolutely > > silly. > > I have one serial port in the system, it shares console, and the > communications port for the application. (But I guess that is besides the > point).
In which case communications over that port could be unreliable. What if the kernel decides to spit out a message in the middle of your applications data transfer? If you're using a serial port for a data application, don't make it the kernel console. > When the common serial core initialises the UART, and sees that it has the > capability to do HW flow control - it enables it, asserting the pin, even if > I don't want it at that moment in time. > > The real issue is that there is some legacy equipment, which gets confused if > it sees glitches on RTS (which happens today, when serial core init asserts > RTS, and then the the main application turns it off)... > > How do I set the set up the UART, so RTS is avaliable, but not enabled? No idea, sorry. It's not something any Linux kernel version has ever supported, and since I no longer do serial support it's not something I'd be involved with anymore. All I will say is that thinking about keying such a decision off the kernel console= parameter is absolutely silly - the console= parameter has nothing to do with the serial port's userspace settings. -- Russell King Linux kernel 2.6 ARM Linux - http://www.arm.linux.org.uk/ maintainer of: - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
