Re: [PATCH RT] tty: serial: st-asc: Make the locking RT aware

From: Steven Rostedt
Date: Tue Mar 21 2017 - 16:16:37 EST


On Tue, 21 Mar 2017 19:51:47 +0100 (CET)
Thomas Gleixner <tglx@xxxxxxxxxxxxx> wrote:

> On Tue, 21 Mar 2017, Steven Rostedt wrote:
> > > /*
> > > * Disable interrupts so we don't get the IRQ line
> > > bouncing
> >
> > I'm nervous about the above comment, which in full is:
> >
> > /*
> > * Disable interrupts so we don't get the IRQ line bouncing
> > * up and down while interrupts are disabled.
> > */
> >
> > I'm not sure if disabling interrupts helps on an SMP system. This
> > patch does change what happens when port->sysrq is set. But I'm not
> > sure we care.
>
> It disables interrupts at the device level which obviously helps
> whether on SMP or not.
>

OK, so this has nothing to do with the local_irq_save() that is being
removed, which would be fine then.


-- Steve