• Lars Poeschel's avatar
    auxdisplay: charlcd: Do not print chars at end of line · af9470b2
    Lars Poeschel authored
    Skip printing characters at the end of a display line. This fits to the
    behaviour we already had, that the cursor is nailed to the last position
    of a line.
    This might slightly change behaviour.
    On hd44780 displays with one or two lines the previous implementation
    did still write characters to the buffer of the display even if they are
    currently not visible. The shift_display command could be used to set
    the "viewing window" to a new position in the buffer and then you could
    see the characters previously written.
    This described behaviour does not work for hd44780 displays with more
    than two display lines. There simply is not enough buffer.
    So the behaviour was a bit inconsistent across different displays.
    The new behaviour is to stop writing characters at the end of a visible
    line, even if there would be room in the buffer. This allows us to have
    an easy implementation, that should behave equal on all supported
    displays. This is not hd44780 hardware dependent anymore.
    Reviewed-by: default avatarWilly Tarreau <w@1wt.eu>
    Signed-off-by: default avatarLars Poeschel <poeschel@lemonage.de>
    Signed-off-by: default avatarMiguel Ojeda <ojeda@kernel.org>
    af9470b2
charlcd.c 15.1 KB