Re: [libvirt] [PATCH] char: drop data written to a disconnected pty

Hi ----- Original Message ----- > When a serial port writes data to a pty that's disconnected, drop the > data and return the length dropped. This avoids triggering pointless > retries in callers like the 16550A serial_xmit(), and causes > qemu_chr_fe_write() to write all data to the log file, rather than > logging only while a pty client like virsh console happens to be > connected. > > Signed-off-by: Ed Swierk <eswierk(a)skyportsystems.com&gt; > --- > qemu-char.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/qemu-char.c b/qemu-char.c > index 676944a..ccb6923 100644 > --- a/qemu-char.c > +++ b/qemu-char.c > @@ -1528,7 +1528,7 @@ static int pty_chr_write(CharDriverState *chr, const > uint8_t *buf, int len) > /* guest sends data, check for (re-)connect */ > pty_chr_update_read_handler_locked(chr); > if (!s->connected) { > - return 0; > + return len; I think this can be confusing if some backends silently drop the data (under disconnected state), while other don't. Perhaps we should have instead a new common chardev property "hup-drop" ? (suggestions for better name welcome)

> } > } > return io_channel_send(s->ioc, buf, len); > -- > 1.9.1 > >