Re: IOLog at interrupt?
Re: IOLog at interrupt?
- Subject: Re: IOLog at interrupt?
- From: Godfrey van der Linden <email@hidden>
- Date: Mon, 12 Nov 2001 13:38:42 -0800
I think you are confusing the IOFilterInterruptEventSource FIlter and
Action routines.
Specifically the Action context is just the work loop. In general
while you are on the work loop context you can do anything you want,
except block for 'too' long.
The Filter is called on the primary hardware interrupt context. Very
little of the system is available at this time. The IOLog doc says
that you can't run at interrupt time, the sub text is that you can't
call it at hardware interrupt time, or in IOKit terms at Filter time.
Does this help?
Godfrey
At 15:34 -0500 01-11-12, Chris Edgington wrote:
The docs for IOLog say "IOLog should not be called from interrupt context."
However, it appears that Apple breaks this rule - in
AppleUSBOHCI_Interrupts.cpp they definitely call IOLog from PollInterrupts -
which is called from InterruptHandler. Am I missing something or is the doc
for IOLog not right? I'm porting some OS9 code to OSX. We've used DCON for
debug output in the past, I'm trying to determine of IOLog will meet our
needs as a replacement for DCON on OSX.