On Sat, Jul 04, 2020 at 02:35:46PM +0300, Andy Shevchenko wrote:
> On Fri, Jul 3, 2020 at 1:32 PM Sergey Senozhatsky
> <sergey.senozhat...@gmail.com> wrote:
> > On (20/07/02 09:05), Tony Lindgren wrote:
> > > * Sergey Senozhatsky <sergey.senozhat...@gmail.com> [200702 05:13]:
> > > > On (20/06/30 11:02), Tony Lindgren wrote:
...
> > This is, basically, an equivalent of
> >
> > ---
> > drivers/tty/serial/8250/8250_port.c | 5 +----
> > 1 file changed, 1 insertion(+), 4 deletions(-)
> >
> > diff --git a/drivers/tty/serial/8250/8250_port.c
> > b/drivers/tty/serial/8250/8250_port.c
> > index d64ca77d9cfa..dba7747d2ddd 100644
> > --- a/drivers/tty/serial/8250/8250_port.c
> > +++ b/drivers/tty/serial/8250/8250_port.c
> > @@ -2275,6 +2275,7 @@ int serial8250_do_startup(struct uart_port *port)
> >
> > if (port->irq && !(up->port.flags & UPF_NO_THRE_TEST)) {
> > unsigned char iir1;
> > +
> > /*
> > * Test for UARTs that do not reassert THRE when the
> > * transmitter is idle and the interrupt has already
> > @@ -2284,8 +2285,6 @@ int serial8250_do_startup(struct uart_port *port)
> > * allow register changes to become visible.
> > */
> > spin_lock_irqsave(&port->lock, flags);
> > - if (up->port.irqflags & IRQF_SHARED)
> > - disable_irq_nosync(port->irq);
> >
> > wait_for_xmitr(up, UART_LSR_THRE);
> > serial_port_out_sync(port, UART_IER, UART_IER_THRI);
> > @@ -2297,8 +2296,6 @@ int serial8250_do_startup(struct uart_port *port)
> > iir = serial_port_in(port, UART_IIR);
> > serial_port_out(port, UART_IER, 0);
> >
> > - if (port->irqflags & IRQF_SHARED)
> > - enable_irq(port->irq);
> > spin_unlock_irqrestore(&port->lock, flags);
> >
> > /*
>
> ...which effectively is a revert of
>
> 768aec0b5bcc ("serial: 8250: fix shared interrupts issues with SMP and
> RT kernels")
(without c389d27b5e64 ("8250.c: port.lock is irq-safe") applied)
--
With Best Regards,
Andy Shevchenko
