135  * - interrupt occurs, ecpp_isr() checks if all the data was transferred, if so
141  * interrupt; ecpp_isr() will then look if there is more data and if so
142  * triggers the soft interrupt, which transfers the next byte. PIO method
155  *   (and also nAck in Nibble Mode) which results in an interrupt on the host;
3057 	 * interrupt may occur while other thread is holding the lock  in ecpp_isr()
3059 	 * since it cannot cancel the interrupt thread,  in ecpp_isr()
3061 	 * telling interrupt handler to exit immediately  in ecpp_isr()
3116 	 * check if interrupt is for this device:  in ecpp_isr()
3127 		 * so if DSR is read after interrupt occured, but before  in ecpp_isr()
3129 		 * as a result, we can miss a service interrupt in PIO mode  in ecpp_isr()
3133 		 * this workaround lets us not to miss an interrupt  in ecpp_isr()
3135 		 * also, nErr interrupt (ECP mode) not always reflected in DCSR  in ecpp_isr()
3149 	/* the intr is for us - check all possible interrupt sources */  in ecpp_isr()
3153 		/* we are expecting a data transfer interrupt */  in ecpp_isr()
3208 		/* last unexpected interrupt was long ago */  in ecpp_isr()
3212 		/* last unexpected interrupt was recently */  in ecpp_isr()
3220 		cmn_err(CE_NOTE, "%s%d: too many interrupt requests",  in ecpp_isr()
3280  * DMA completion interrupt handler
3290 	/* we are expecting a data transfer interrupt */  in ecpp_dma_ihdlr()
3331  * ecpp_pio_ihdlr() is a PIO interrupt processing routine
3350 	 * otherwise trigger a soft interrupt to send the next byte  in ecpp_pio_ihdlr()
3404  * Backchannel request interrupt handler
3439 		 *   periph sets nAck high to generate an interrupt  in ecpp_nErr_ihdlr()
3441 		 * Interface is in Interrupt Phase  in ecpp_nErr_ihdlr()
3800  * so that when the DMA counter reaches zero (and an interrupt occurs)
5096 			 * enable nAck interrupt to get a backchannel request  in ecpp_idle_phase()
5521  * in this case - set interrupt characteristic
5580 	/* low interrupt polarity */  in pc97317_config_chip()
5634  * in this case - set interrupt polarity
5695 	/* ACK and disable the TC interrupt */  in cheerio_dma_stop()
6253 	 * Allocate, initialize and install interrupt counter kstat  in ecpp_kstat_init()