[added linuxppc-dev since it's PPC relevant too]
On Tuesday 30 October 2007, Josh Boyer wrote:
> On Mon, 29 Oct 2007 15:45:03 -0400
>
> [email protected] (Lennart Sorensen) wrote:
> > On Mon, Oct 29, 2007 at 03:22:27PM +0100, Stefan Roese wrote:
> > > I'm trying to implement support for a board specific watchdog on a
> > > PPC440EPx board with a very short timeout. In this case, the watchdog
> > > has to be "kicked" at least every 100ms, even while booting and the
> > > real watchdog driver not running yet. While looking for trigger places
> > > in the kernel source, I noticed the already existing
> > > "touch_nmi_watchdog()" function, which seems to be doing what I need.
> > > Even if the name not exactly matches my hardware setup.
> > >
> > > My question now is, is it recommended to use this
> > > touch_nmi_watchdog() "infrastructure" for my PPC custom specific
> > > watchdog during bootup? And if yes, should it perhaps be renamed to a
> > > more generic name, like "touch_watchdog"?
> > >
> > > Please advise. Thanks.
> >
> > No idea really. Who would design a watchdog with such a short trigger
> > time? That doesn't seem to be useful in any way.
It definitely is useful in our case, since its a requirement for
this "critical" project. It's not needed to have such a short trigger time
while booting, but unfortunately this external watchdog only supports one
fixed timeout.
> To some degree, it's configurable.
No, I'm afraid it's not configurable in this case.
> But the generic question still
> stands. It seems like a decent idea to me. Making touch_watchdog (or
> whatever it winds up being called) nice across arches might be fun.
I already have it running on my system using a quick hack (see patch below) in
include/asm-ppc/nmi.h (yes, still arch/ppc for now :-( ). But for a clean
implementation, that has chances for upstream merge (in arch/powerpc later),
I would really like to hear if I should move on further this way.
My impression is, that changing the name from touch_nmi_watchdog() to
something like touch_watchdog(), and therefore touching lots of files, makes
it more unlikely that this resulting patch will get accepted. But
implementing this bootup watchdog support in asm-ppc(asm-powerpc)/nmi.h
header seems also not totally correct, since it's not really an NMI in this
case.
Any thoughts on this?
Thanks.
Best regards,
Stefan
diff --git a/include/asm-ppc/nmi.h b/include/asm-ppc/nmi.h
new file mode 100644
index 0000000..f18862b
--- /dev/null
+++ b/include/asm-ppc/nmi.h
@@ -0,0 +1,16 @@
+/*
+ * linux/include/asm-ppc/nmi.h
+ */
+#ifndef ASM_NMI_H
+#define ASM_NMI_H
+
+#ifdef BOARD_WATCHDOG_FUNC
+#define touch_nmi_watchdog BOARD_WATCHDOG_FUNC
+#else
+static inline void touch_nmi_watchdog(void)
+{
+ touch_softlockup_watchdog();
+}
+#endif
+
+#endif /* ASM_NMI_H */
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [email protected]
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
[Index of Archives]
[Kernel Newbies]
[Netfilter]
[Bugtraq]
[Photo]
[Stuff]
[Gimp]
[Yosemite News]
[MIPS Linux]
[ARM Linux]
[Linux Security]
[Linux RAID]
[Video 4 Linux]
[Linux for the blind]
[Linux Resources]
