Lines Matching refs:filter
44 @discussion An interrupt event source that calls the client to determine if a interrupt event needs to be scheduled on the work loop. A filter interrupt event source call's the client in the primary interrupt context, the client can then interrogate its hardware and determine if the interrupt needs to be processed yet.
46 As the routine is called in the primary interrupt context great care must be taken in the writing of this routine. In general none of the generic IOKit environment is safe to call in this context. We intend this routine to be used by hardware that can interrogate its registers without destroying state. Primarily this variant of event sources will be used by drivers that share interrupts. The filter routine will determine if the interrupt is a real interrupt or a ghost and thus optimise the work thread context switch away.
48 If you are implementing 'SoftDMA' (or pseudo-DMA), you may not want the I/O Kit to automatically start your interrupt handler routine on your work loop when your filter routine returns true. In this case, you may choose to have your filter routine schedule the work on the work loop itself and then return false. If you do this, the interrupt will not be disabled in hardware and you could receive additional primary interrupts before your work loop���level service routine completes. Because this scheme has implications for synchronization between your filter routine and your interrupt service routine, you should avoid doing this unless your driver requires SoftDMA.
100 @param filter 'C' Function to call when interrupt occurs.
107 Filter filter,
115 @param filter 'C' Function to call in primary interrupt context.
122 Filter filter,
129 @discussion Cause the work loop to schedule the interrupt action even if the filter routine returns 'false'. Note well the interrupting condition MUST be cleared from the hardware otherwise an infinite process interrupt loop will occur. Use this function when SoftDMA is desired. See $link IOFilterInterruptSource::Filter */
138 @abstract Override $link IOInterruptEventSource::normalInterruptOccured to make a filter callout. */
142 @abstract Override $link IOInterruptEventSource::disableInterruptOccurred to make a filter callout. */