Subject: Re: [PATCH] PPC: Enable the Watchdog vector for 405

From: Jason Gunthorpe <[email-masked]>
Date: Mon, 1 Oct 2012 10:25:47 -0600

On Mon, Oct 01, 2012 at 08:16:29AM -0400, Josh Boyer wrote:
> On Sun, Sep 30, 2012 at 7:27 PM, Jason Gunthorpe
> <[email-masked]> wrote:
> > Move the body of the PIT exception out of line to make room.
> 
> What boards did you test this on?  What driver are you using for the
> watchdog?

Tested on a 405F6 core (Xilinx's variant), the board is custom, and
the control for the watchdog SPRs was bundled into a watchdog driver
for the board's watchdog controller.

> >  /* 0x1010 - Fixed Interval Timer (FIT) Exception
> >  */
> > -       STND_EXCEPTION(0x1010,  FITException,           unknown_exception)
> > +//     STND_EXCEPTION(0x1010,  FITException,           unknown_exception)
> 
> Please just move the #endif for the #if 0 up instead of putting a C++
> style comment here.

Sure
 
> >  /* 0x1020 - Watchdog Timer (WDT) Exception
> >  */
> > -#ifdef CONFIG_BOOKE_WDT
> >         CRITICAL_EXCEPTION(0x1020, WDTException, WatchdogException)
> > -#else
> > -       CRITICAL_EXCEPTION(0x1020, WDTException, unknown_exception)
> > -#endif
> > -#endif
> 
> Please leave this wrapped in CONFIG_BOOKE_WDT.  I don't agree with
> unconditionally enabling this for every 405 chip out there.

What are you concerned with? If some core varient does not put a
watchdog there, then you still get a panic from the default watchdog
exception handler..

> > -#ifdef CONFIG_BOOKE_WDT
> > +#if defined(CONFIG_BOOKE_WDT) | defined(CONFIG_40x)
> 
> Pretty sure you meant || here?  Thought if you just enable the existing
> config option, I don't think you'd need to edit this file at all.

Yes, I didn't want to use BOOKE_WDT because I have not tested that
driver, nor do I want that driver included in my kernel.. I think the
watchdog driver in use should be orthogonal to having the exception
wired in?

Jason