I'm having problems getting xon/xoff flow control in the new rp2.c
driver working.
The problem is that the driver's set_termios() function is not getting
called when the user-space application calls tcsetattr() to change
IXON, IXOFF, IXANY, c_cc[VSTOP], or c_cc[VSTART].
According to Documentation/serial/driver:
set_termios(port,termios,oldtermios)
Change the port parameters, including word length, parity, stop
bits.
[...]
Other flags may be used (eg, xon/xoff characters) if your
hardware supports hardware "soft" flow control.
My hardware supports xon/xoff flow control, so how do I use other
flags?
It looks like serial_core.c is hiding some termios changes from
low-level drivers:
1193 static void uart_set_termios(struct tty_struct *tty,
1194 struct ktermios *old_termios)
1195 {
1196 struct uart_state *state = tty->driver_data;
1197 unsigned long flags;
1198 unsigned int cflag = tty->termios->c_cflag;
1199
1200
1201 /*
1202 * These are the bits that are used to setup various
1203 * flags in the low level driver. We can ignore the Bfoo
1204 * bits in c_cflag; c_[io]speed will always be set
1205 * appropriately by set_termios() in tty_ioctl.c
1206 */
1207 #define RELEVANT_IFLAG(iflag) ((iflag) & (IGNBRK|BRKINT|IGNPAR|PARMRK|INPCK))
1208 if ((cflag ^ old_termios->c_cflag) == 0 &&
1209 tty->termios->c_ospeed == old_termios->c_ospeed &&
1210 tty->termios->c_ispeed == old_termios->c_ispeed &&
1211 RELEVANT_IFLAG(tty->termios->c_iflag ^ old_termios->c_iflag) == 0) {
1212 return;
1213 }
When I look at omap-serial.c, it looks like it's trying to handle
IXANY, IXON and IXOFF the same way I am -- but I don't get notified
when they change.
I don't understand...
--
Grant Edwards grant.b.edwards Yow! If I am elected no one
at will ever have to do their
gmail.com laundry again!
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