On Thu, Jul 12, 2018 at 12:30:01PM -0600, Tycho Andersen wrote:

On Thu, Jul 12, 2018 at 08:25:45PM +0200, Greg Kroah-Hartman wrote:

quoted

On Thu, Jul 12, 2018 at 12:18:46PM -0600, Tycho Andersen wrote:

quoted

On Thu, Jul 12, 2018 at 05:40:15PM +0200, Greg Kroah-Hartman wrote:

quoted

On Thu, Jul 12, 2018 at 09:08:22AM -0600, Tycho Andersen wrote:

quoted

On Thu, Jul 12, 2018 at 05:04:38PM +0200, Greg Kroah-Hartman wrote:

quoted

On Wed, Jul 11, 2018 at 10:07:44AM -0600, Tycho Andersen wrote:

quoted

+	if (uport)
+		spin_lock_irqsave(&uport->lock, flags);

That's the same thing as just calling uart_port_lock(), why aren't you
doing that?

Because the compiler can't seem to "see" through the macros/ref calls,
and I get the warning I mentioned here if I use them:

https://lkml.org/lkml/2018/7/6/840

What horrible version of gcc are you using that give you that?  Don't
open-code things just because of a broken compiler.

I've tried with both 7.3.0 and 5.4.0. I think the reason we see this
here but not elsewhere in the file is because there's an actual
function call (free_page()) in the critical section.

If we move that out, something like the below patch, it all works for
me.

Ick.  Which version of this series had the problem?  Let me test it out
here...

v3, if you remove the initialization of flags from both functions you
should see it.

Ok, I tried v3 out and yes, you are right, removing the "= 0" causes gcc
to complain.  The compiler is being dumb here, so I'll just leave it
as-is.  I've queued up the v3 version now, thanks for sticking with
this.

greg k-h