FILTER_SCHEDULE_THREAD is not a bit-value
Max Khon
fjoe at samodelkin.net
Mon Jan 30 17:18:57 UTC 2012
Hello!
sys/bus.h documents the following semantics for FILTER_SCHEDULE_THREAD:
/**
* @brief Driver interrupt filter return values
*
* If a driver provides an interrupt filter routine it must return an
* integer consisting of oring together zero or more of the following
^^^^^^^
* flags:
*
* FILTER_STRAY - this device did not trigger the interrupt
* FILTER_HANDLED - the interrupt has been fully handled and can be EOId
* FILTER_SCHEDULE_THREAD - the threaded interrupt handler should be
* scheduled to execute
*
* If the driver does not provide a filter, then the interrupt code will
* act is if the filter had returned FILTER_SCHEDULE_THREAD. Note that it
* is illegal to specify any other flag with FILTER_STRAY and that it is
* illegal to not specify either of FILTER_HANDLED or FILTER_SCHEDULE_THREAD
* if FILTER_STRAY is not specified.
*/
#define FILTER_STRAY 0x01
#define FILTER_HANDLED 0x02
#define FILTER_SCHEDULE_THREAD 0x04
But actually FILTER_SCHEDULE_THREAD is not used as a bit-value (see
kern/kern_intr.c):
if (!thread) {
if (ret == FILTER_SCHEDULE_THREAD)
thread = 1;
}
There is at least one in-tree driver that could be broken because of
this (asmc(8), but I found the problem with some other out-of-tree
driver).
This should be "if (ret & FILTER_SCHEDULE_THREAD)" instead. Attached
patch fixes the problem.
What do you think?
Max
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