INTEL_QEPFLT
reg = INTEL_QEPFLT_MAX_COUNT(intel_qep_readl(qep, INTEL_QEPFLT));
intel_qep_writel(qep, INTEL_QEPFLT, length);
qep->qepflt = intel_qep_readl(qep, INTEL_QEPFLT);
intel_qep_writel(qep, INTEL_QEPFLT, qep->qepflt);