On Wed, Jul 30, 2025 at 03:13:31AM +0000, dm...@proton.me wrote: > From: Denis Mukhin <dmuk...@ford.com> > > As it stands, polling timer is kept in the list of timers even after the > interrupts have been enabled / polling disabled on ns16550-compatible UART. > > Ensure polling timer is removed from the timer list once UART interrupts are > enabled. > > Signed-off-by: Denis Mukhin <dmuk...@ford.com> > --- > xen/drivers/char/ns16550.c | 4 ++++ > 1 file changed, 4 insertions(+) > > diff --git a/xen/drivers/char/ns16550.c b/xen/drivers/char/ns16550.c > index df7fff7f81df..299773d80065 100644 > --- a/xen/drivers/char/ns16550.c > +++ b/xen/drivers/char/ns16550.c > @@ -191,6 +191,10 @@ static void cf_check ns16550_interrupt(int irq, void > *dev_id) > struct serial_port *port = dev_id; > struct ns16550 *uart = port->uart; > > + /* Ensure polling timer is disarmed and removed from the timer list. */ > + if ( !uart->intr_works ) > + kill_timer(&uart->timer);
I think if anything you should issue a stop_timer() call, but not a kill_timer() one, otherwise the uart code will hit an ASSERT when calling set_timer() from ns16550_setup_postirq()? (that's from _ns16550_resume()). Thanks, Roger.
