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

@ -290,7 +290,7 @@ static int usbredir_write(void *priv, uint8_t *data, int count)
r = qemu_chr_fe_write(dev->cs, data, count);
if (r < count) {
if (!dev->watch) {
dev->watch = qemu_chr_fe_add_watch(dev->cs, G_IO_OUT,
dev->watch = qemu_chr_fe_add_watch(dev->cs, G_IO_OUT|G_IO_HUP,
usbredir_write_unblocked, dev);
}
if (r < 0) {