On Mon, Nov 23, 2009 at 9:12 PM, Greg KH <gre...@gmail.com> wrote: > On Mon, Nov 23, 2009 at 12:04 AM, pavan savoy <pavan.sa...@gmail.com> wrote: >> Hi, >> >> Is it possible to install a line discipline somehow from the kernel >> space it-self ? > > What do you mean "install"? Load a module? Or something else? Yeah, install I meant is something like doing an EXPORT_SYMBOL of tty_ldisc_put or something, with that any ldisc driver can,
do a tty_register_ldisc to register itself as a line discipline and then based on a certain user input can perform a tty_ldisc_put (although I understand, it would be just over-riding the current ldisc) > >> Why such an requirement you may ask - For every line discipline that >> needs to work over an ttyS, today linux requires a daemon, so if I >> have 3 uarts and have 3 different ldiscs on it, it just adds me 3 >> daemons for no reason at all !! >> [those daemons do nothing but do an ioctl TIOCSETD and don't close the >> fd- to retain the line disc] > > Is there some problem with these extra processes that they are causing you? Yes, they are kind of un-necessary. 1 daemon just to do an open(/dev/ttyS1) do an ioctl TIOCSETD on the fd, and then sleep, and close fd on exit. case of N_HCI (bluetooth n_hci line discipline). > > And those ldiscs are creating those daemons for a good reason, right? If not, > then change ldisc to use one that does not have an extra process. > I didn't understand this. I could not find a ldisc which doesn't have a corresponding daemon. kernel doesn't allow ldisc drivers to force the ldisc, it has to be done by a daemon which directly talks to TTY layer to do an ioctl TIOCSETD. > good luck, > > greg k-h > > -- > unsubscribe: android-kernel+unsubscr...@googlegroups.com > website: http://groups.google.com/group/android-kernel -- --Pavan Savoy -- unsubscribe: android-kernel+unsubscr...@googlegroups.com website: http://groups.google.com/group/android-kernel
