[PATCH] Heartbeat LED for iBook

Joerg Dorchain joerg at dorchain.net
Fri Jan 28 03:36:06 EST 2005

On Wed, Jan 26, 2005 at 12:35:54PM +0100, Nico Schottelius wrote:
> Joerg Dorchain [Tue, Jan 18, 2005 at 10:42:16AM +0100]:
> > [heartbeat blink patch]
> Well, wouldn't it make much more sense to write a
> /dev/frontled to access it via userspace? 

Well, only some hardware supports something that can be used as a HB
LED, so IMHO yet another (misc-) device node is not completely

Then again, the current implemenation was more or less directly copied
from arch/m68k and the pmac IDE driver, my only "own" contribution was
taking the different HZ value into account, and this only in the
simplest possible way.

The original idea behing the m68k HB was to see wether the machine has
crashed so far that even interrupts weren't working any more, which is
sometime very hard to distiguish from very high load (>20). Obiously,
this is best done in kernel space. The load-dependeant blinking
frequency just made it perfect for its original purpose ;-)

I still consider it more a development aid than a real user feature.


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