Don't store the SIRTP request bit in the register state. It will otherwise become sticky and could request an Interrupt Remap Table Pointer update on each command register write.
Found while starting to emulate IR in QEMU, not by observing problems on real hardware. Signed-off-by: Jan Kiszka <[email protected]> --- drivers/iommu/intel_irq_remapping.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) diff --git a/drivers/iommu/intel_irq_remapping.c b/drivers/iommu/intel_irq_remapping.c index 0df41f6..a872874 100644 --- a/drivers/iommu/intel_irq_remapping.c +++ b/drivers/iommu/intel_irq_remapping.c @@ -438,8 +438,7 @@ static void iommu_set_irq_remapping(struct intel_iommu *iommu, int mode) (addr) | IR_X2APIC_MODE(mode) | INTR_REMAP_TABLE_REG_SIZE); /* Set interrupt-remapping table pointer */ - iommu->gcmd |= DMA_GCMD_SIRTP; - writel(iommu->gcmd, iommu->reg + DMAR_GCMD_REG); + writel(iommu->gcmd | DMA_GCMD_SIRTP, iommu->reg + DMAR_GCMD_REG); IOMMU_WAIT_OP(iommu, DMAR_GSTS_REG, readl, (sts & DMA_GSTS_IRTPS), sts); -- 1.8.1.1.298.ge7eed54 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
