From 525209ac9465f37a9ba292f1ff138dd80768e869 Mon Sep 17 00:00:00 2001 From: Denys Vlasenko Date: Mon, 26 Sep 2016 14:37:12 +0200 Subject: libbb/speed_table.c: expand comments Signed-off-by: Denys Vlasenko --- libbb/speed_table.c | 17 ++++++++++++++++- 1 file changed, 16 insertions(+), 1 deletion(-) diff --git a/libbb/speed_table.c b/libbb/speed_table.c index 13dc9c73a..11ced01d0 100644 --- a/libbb/speed_table.c +++ b/libbb/speed_table.c @@ -103,8 +103,23 @@ static const struct speed_map speeds[] = { {B4000000, 4000000/200 + 0x8000u}, #endif /* 4000000/200 = 0x4e20, bit#15 still does not interfere with the value */ +/* (can use /800 if higher speeds would appear, /1600 won't work for B500000) */ }; +/* + * TODO: maybe we can just bite the bullet, ditch the table and use termios2 + * Linux API (supports arbitrary baud rates, no Bxxxx mess needed)? Example: + * + * #include + * #include + * struct termios2 t; + * ioctl(fd, TCGETS2, &t); + * t.c_ospeed = t.c_ispeed = 543210; + * t.c_cflag &= ~CBAUD; + * t.c_cflag |= BOTHER; + * ioctl(fd, TCSETS2, &t); + */ + enum { NUM_SPEEDS = ARRAY_SIZE(speeds) }; unsigned FAST_FUNC tty_baud_to_value(speed_t speed) @@ -114,7 +129,7 @@ unsigned FAST_FUNC tty_baud_to_value(speed_t speed) do { if (speed == speeds[i].speed) { if (speeds[i].value & 0x8000u) { - return ((unsigned long) (speeds[i].value) & 0x7fffU) * 200; + return ((unsigned)(speeds[i].value) & 0x7fffU) * 200; } return speeds[i].value; } -- cgit v1.2.3