From 3974e544393bd5a720838cbf4790c532bca2aae4 Mon Sep 17 00:00:00 2001
From: Josh Blum <josh@joshknows.com>
Date: Fri, 22 Oct 2010 16:59:12 -0700
Subject: dbsrx: reject asymmetric clocks (odd divisors)

---
 host/lib/usrp/dboard/db_dbsrx.cpp | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/host/lib/usrp/dboard/db_dbsrx.cpp b/host/lib/usrp/dboard/db_dbsrx.cpp
index 0b8b4db83..aecd7249d 100644
--- a/host/lib/usrp/dboard/db_dbsrx.cpp
+++ b/host/lib/usrp/dboard/db_dbsrx.cpp
@@ -236,8 +236,10 @@ void dbsrx::set_lo_freq(double target_freq){
     bool update_filter_settings = false;
     //choose refclock
     std::vector<double> clock_rates = this->get_iface()->get_clock_rates(dboard_iface::UNIT_RX);
+    const double max_clock_rate = std::sorted(clock_rates).back();
     BOOST_FOREACH(ref_clock, std::reversed(std::sorted(clock_rates))){
         if (ref_clock > 27.0e6) continue;
+        if (size_t(max_clock_rate/ref_clock)%2 == 1) continue; //reject asymmetric clocks (odd divisors)
 
         //choose m_divider such that filter tuning constraint is met
         m = 31;
-- 
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