Re: [PATCH] For test only: pmac_zilog fixes (cups lockup at boot):

Benjamin Herrenschmidt
2004-03-05T11:16:11Z

On Fri, 2004-03-05 at 20:48, Russell King wrote:
> On Fri, Mar 05, 2004 at 08:29:12PM +1100, Benjamin Herrenschmidt wrote:
> >
> > > Yes, I know - but the point is its impossible to review, and I think
> > > you at least have an extra level of locking which isn't needed.
> > >
> > > But I wouldn't know because of the huge number of changes which make
> > > it impossible to read.
> >
> > That semaphore locking is only used to guard open/close against the
> > power management callback. It greatly simplify the deal with the shared
> > irq (the irq is shared between both ports). It's not used during
> > normal operations.
>
> Err. What power management callback? Are you not using uart_suspend_port
> and uart_resume_port?
>
> These functions do all the locking for you already - using state->sem.

Well... I could, but I have additional crap related to shutting
the SCC down. I need to disable_irq() at the irq controller level
after both ports have been shut down only, since a down SCC would
leave a dangling irq line...

> Like I said, I can't see the twigs for the forest due to the shear
> noise caused by the up -> uap change.

Yah, I know. Difficult to split though. I'd suggest you just look
at the driver as a whole after the patch is applied ;)

Ben.