On 2012-09-17 19:46, Gilles Chanteperdrix wrote: > ipipe_end is a nop when called from primary domain, yes, but this is not > very different from edge irqs. Also, fasteoi become a bit like MSI: in > the same way as we can not mask MSI from primary domain, we should not > mask IO-APIC fasteoi irqs, because the cost is too prohibitive. If we > can live with MSI without masking them in primary mode, I guess we can > do the same with fasteoi irqs.
MSIs are edge triggered, fasteois are still level-based. They require masking at the point you defer them - what we do and what Linux may even extend beyond that. If you mask them by raising the task priority, you have to keep it raised until Linux finally handled the IRQ. Or you decide to mask it at IO-APIC level again. If you keep the TPR raised, you will block more than what Linux wants to block. Jan -- Siemens AG, Corporate Technology, CT RTC ITP SDP-DE Corporate Competence Center Embedded Linux _______________________________________________ Xenomai mailing list Xenomai@xenomai.org http://www.xenomai.org/mailman/listinfo/xenomai
