| Message ID | 1467631532-8122-3-git-send-email-mark.rutland@arm.com |
|---|---|
| State | New |
| Headers | show |
diff --git a/drivers/bus/arm-cci.c b/drivers/bus/arm-cci.c index a49b283..ffce9e3 100644 --- a/drivers/bus/arm-cci.c +++ b/drivers/bus/arm-cci.c @@ -881,7 +881,8 @@ static int pmu_request_irq(struct cci_pmu *cci_pmu, irq_handler_t handler) * This should allow handling of non-unique interrupt for the counters. */ for (i = 0; i < cci_pmu->nr_irqs; i++) { - int err = request_irq(cci_pmu->irqs[i], handler, IRQF_SHARED, + int err = request_irq(cci_pmu->irqs[i], handler, + IRQF_NOBALANCING | IRQF_NO_THREAD, "arm-cci-pmu", cci_pmu); if (err) { dev_err(&pmu_device->dev, "unable to request IRQ%d for ARM CCI PMU counters\n",
Currently the IRQ core is permitted to make the CCI PMU IRQ handler threaded, and will allow userspace to change the CPU affinity of the interrupt behind our back. Both of these could violate our synchronisation requirements with the core perf code, which relies upon strict CPU affinity and disabling of interrupts to guarantee mutual exclusion in some cases. As with the CPU PMU drivers, we should request the interrupt with IRQF_NOBALANCING and IRQF_NO_THREAD, to avoid these issues. At the same time, we drop IRQF_SHARED. The interrupt is not shared in practice, and the driver detects and skips duplicate IRQs at probe time, so it is not necessary. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Cc: Marc Zyngier <marc.zyngier@arm.com> Cc: Punit Agrawal <punit.agrawal@arm.com> Cc: Suzuki K Poulose <suzuki.poulose@arm.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Olof Johansson <olof@lixom.net> Cc: Arnd Bergmann <arnd@arndb.de> Cc: <arm@kernel.org> --- drivers/bus/arm-cci.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) -- 1.9.1 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel