Re: [Qemu-devel] [PATCH v2] Remove unwanted crlf conversion in serial

[Markus Armbruster]

Patryk Olszewski <address@hidden> writes:

> This patch fixes bug in serial that made it almost impossible for guest
> to communicate with devices through host's serial.

Well, "almost impossible" for some applications.  Text works fine.  But
I get what you mean.

> OPOST flag in c_oflag enables output processing letting other flags in
> c_oflag take effect. Usually in c_oflag ONLCR flag is also set, which
> causes crlf to be sent in place of lf. This breaks binary transmissions.
> Unsetting OPOST flag turns off any output processing which fixes the bug.
>
> Bug reports related:
> https://bugs.launchpad.net/qemu/+bug/1772086
> https://bugs.launchpad.net/qemu/+bug/1407813
> https://bugs.launchpad.net/qemu/+bug/1715296
> also
> https://lists.nongnu.org/archive/html/qemu-devel/2006-06/msg00196.html
>
> Signed-off-by: Patryk Olszewski <address@hidden>
> ---
>  chardev/char-serial.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/chardev/char-serial.c b/chardev/char-serial.c
> index feb52e5..ae548d2 100644
> --- a/chardev/char-serial.c
> +++ b/chardev/char-serial.c
> @@ -139,7 +139,7 @@ static void tty_serial_init(int fd, int speed,
>  
>      tty.c_iflag &= ~(IGNBRK | BRKINT | PARMRK | ISTRIP
>                       | INLCR | IGNCR | ICRNL | IXON);
> -    tty.c_oflag |= OPOST;
> +    tty.c_oflag &= ~OPOST;
>      tty.c_lflag &= ~(ECHO | ECHONL | ICANON | IEXTEN | ISIG);
>      tty.c_cflag &= ~(CSIZE | PARENB | PARODD | CRTSCTS | CSTOPB);
>      switch (data_bits) {

Reviewed-by: Markus Armbruster <address@hidden>