serial: poll the serial console with G_IO_HUP

On FreeBSD polling a master pty while the other end is not connected
with G_IO_OUT only results in an endless wait. This is different from
the Linux behaviour, that returns immediately. In order to demonstrate
this, I have the following example code:

http://xenbits.xen.org/people/royger/test_poll.c

When executed on Linux:

$ ./test_poll
In callback

On FreeBSD instead, the callback never gets called:

$ ./test_poll

So, in order to workaround this, poll the source with G_IO_HUP (which
makes the code behave the same way on both Linux and FreeBSD).

Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Cc: Peter Crosthwaite <peter.crosthwaite@xilinx.com>
Cc: Michael Tokarev <mjt@tls.msk.ru>
Cc: "Andreas Färber" <afaerber@suse.de>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: xen-devel@lists.xenproject.org
[Add hw/char/cadence_uart.c too. - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This commit is contained in:
Roger Pau Monne 2014-05-23 17:57:49 +02:00 committed by Paolo Bonzini
parent 9328cfd2fe
commit e02bc6de30
5 changed files with 7 additions and 5 deletions

View file

@ -306,7 +306,8 @@ static gboolean cadence_uart_xmit(GIOChannel *chan, GIOCondition cond,
memmove(s->tx_fifo, s->tx_fifo + ret, s->tx_count);
if (s->tx_count) {
int r = qemu_chr_fe_add_watch(s->chr, G_IO_OUT, cadence_uart_xmit, s);
int r = qemu_chr_fe_add_watch(s->chr, G_IO_OUT|G_IO_HUP,
cadence_uart_xmit, s);
assert(r);
}