[Qemu-devel] Re: more about serial ports: do they even work?

[Michael Tokarev]

Marcelo Tosatti wrote:
> On Tue, Feb 03, 2009 at 08:41:14AM +0000, Mark Marshall wrote:
[]
> Right. I don't understand the point of converting to an "internal"
> representation of TIOCM control bits. 

<fun mode>
Well, the same goes for the IOCTL values themselves too -- like
this CHR_IOCTL_SERIAL_SET_TIOCM itself.  I mean, TIOCMSET is
the right name for it ;)  But see below.

> CHR_IOCTL_SERIAL_SET_TIOCM is clearly broken as mentioned. It should at 
> least preserve the bits it does not control.
> 
> diff --git a/qemu/qemu-char.c b/qemu/qemu-char.c
> index ac431c7..66971e1 100644
> --- a/qemu/qemu-char.c
> +++ b/qemu/qemu-char.c
> @@ -1063,33 +1063,12 @@ static int tty_serial_ioctl(CharDriverState *chr, int 
> cmd, void *arg)
>          break;
>      case CHR_IOCTL_SERIAL_GET_TIOCM:
>          {
> +            ioctl(s->fd_in, TIOCMGET, arg);
>          }
>          break;

And those parens too, let it die, die! ;)
</fun mode>

Other than that, an.. excellent idea, I wanted to propose
just that when I first saw all this stuff, but was somewhat
afraid.  And I *think* there's at least *some* sense.  Qemu
is a CPU emulator and may work on another arch where those
bits are defined differently.  Maybe that was the reason for
all this converting - to be safe than sorry, so to say.  No?

/mjt