Quoting Chris Wilson (2017-10-20 22:06:39) > The execlists emulation on top of the GuC (used for scheduling and > preemption) depends on the MI_USER_INTERRUPT for its notifications and > tasklet action. As we always employ the irq, there is no advantage in > ever disabling it while we are using the GuC, so allow us to arm the > breadcrumb irq when enabling GuC submission and disarm upon disabling. > The impact should be lessened by the delayed irq disabling we do (we > only disable after receiving an interrupt for which no one was wanting), > but allowing guc to explicitly manage the irq in relation to itself is > simpler and prevents an issue with losing an interrupt for preemption > as it is not coupled to an active request. > > Internally, we add a reference counter (breadcrumbs.irq_users) as a > simple mechanism to allow GuC to keep the breadcrumb irq enabled. It > also means that the missed-breadcrumb timer is permanently active. Scratch that part; the timer is only enabled for waiters. -Chris _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/intel-gfx
