diff --git a/sources b/sources
index 39db599..ec43d92 100644
--- a/sources
+++ b/sources
@@ -1 +1 @@
-b4ac7e2f438fde8d2840efc5beb2cc30  uhd-3.3.2.tar.gz
+304728ac2f3dacfeab3dac611357aeec  uhd-3.4.0.tar.gz
diff --git a/uhd-3.4.0-usrp1-r45-dbsrx-i2c-fix.patch b/uhd-3.4.0-usrp1-r45-dbsrx-i2c-fix.patch
new file mode 100644
index 0000000..ad91af1
--- /dev/null
+++ b/uhd-3.4.0-usrp1-r45-dbsrx-i2c-fix.patch
@@ -0,0 +1,41 @@
+commit 097f20df1653c33035b6dcfefbbef22572426c65
+Author: Josh Blum <josh@joshknows.com>
+Date:   Mon Mar 26 14:25:56 2012 -0700
+
+    dbsrx: limit the USRP1 + DBSRX GPIO clock rate to 4MHz
+    
+    This fixes the lockup/clocking condition when the following hw combo is used:
+    USRP1 r4.5 + DBSRX + another i2c board
+
+diff --git a/host/lib/usrp/dboard/db_dbsrx.cpp b/host/lib/usrp/dboard/db_dbsrx.cpp
+index 846597f..95c5c5d 100644
+--- a/host/lib/usrp/dboard/db_dbsrx.cpp
++++ b/host/lib/usrp/dboard/db_dbsrx.cpp
+@@ -1,5 +1,5 @@
+ //
+-// Copyright 2010-2011 Ettus Research LLC
++// Copyright 2010-2012 Ettus Research LLC
+ //
+ // This program is free software: you can redistribute it and/or modify
+ // it under the terms of the GNU General Public License as published by
+@@ -58,6 +58,8 @@ static const uhd::dict<std::string, gain_range_t> dbsrx_gain_ranges = map_list_o
+     ("GC2", gain_range_t(0, 24, 1))
+ ;
+ 
++static const double usrp1_gpio_clock_rate_limit = 4e6;
++
+ /***********************************************************************
+  * The DBSRX dboard class
+  **********************************************************************/
+@@ -265,6 +267,11 @@ double dbsrx::set_lo_freq(double target_freq){
+     std::vector<double> clock_rates = this->get_iface()->get_clock_rates(dboard_iface::UNIT_RX);
+     const double max_clock_rate = uhd::sorted(clock_rates).back();
+     BOOST_FOREACH(ref_clock, uhd::reversed(uhd::sorted(clock_rates))){
++        //USRP1 feeds the DBSRX clock from a FPGA GPIO line.
++        //make sure that this clock does not exceed rate limit.
++        if (this->get_iface()->get_special_props().soft_clock_divider){
++            if (ref_clock > usrp1_gpio_clock_rate_limit) continue;
++        }
+         if (ref_clock > 27.0e6) continue;
+         if (size_t(max_clock_rate/ref_clock)%2 == 1) continue; //reject asymmetric clocks (odd divisors)
+ 
diff --git a/uhd.spec b/uhd.spec
index 934af57..0d96d24 100644
--- a/uhd.spec
+++ b/uhd.spec
@@ -1,5 +1,5 @@
 # Pull from git
-%global git_tag release_003_003_002
+%global git_tag release_003_004_000
 
 # git clone git://code.ettus.com/ettus/uhd.git
 # cd uhd
@@ -8,7 +8,7 @@
 
 Name:           uhd
 URL:            http://code.ettus.com/redmine/ettus/projects/uhd/wiki
-Version:        3.3.2
+Version:        3.4.0
 Release:        1%{?dist}
 License:        GPLv3+
 BuildRequires:  cmake
@@ -20,6 +20,8 @@ Group:          Applications/Engineering
 Summary:        Universal Hardware Driver for Ettus Research products
 Source0:        %{name}-%{version}.tar.gz
 Source1:        %{name}-limits.conf
+# Upstream commit 097f20df1653c33035b6dcfefbbef22572426c65
+Patch0:         uhd-3.4.0-usrp1-r45-dbsrx-i2c-fix.patch
 
 %description
 The UHD is the universal hardware driver for Ettus Research products.
@@ -28,6 +30,7 @@ future Ettus Research products. It can be used standalone without GNU Radio.
 
 %prep
 %setup -q
+%patch0 -p1 -b .usrp1-r45-dbsrx-i2c-fix
 
 %build
 mkdir host/build
@@ -87,8 +90,7 @@ getent group usrp >/dev/null || groupadd -r usrp >/dev/null
 
 %files
 %doc _tmpdoc/*
-%{_bindir}/uhd_find_devices
-%{_bindir}/uhd_usrp_probe
+%{_bindir}/*
 %config(noreplace) %{_sysconfdir}/udev/rules.d/10-usrp-uhd.rules
 %config(noreplace) %{_sysconfdir}/security/limits.d/*.conf
 %{_libdir}/lib*.so.*
@@ -103,6 +105,12 @@ getent group usrp >/dev/null || groupadd -r usrp >/dev/null
 %doc %{_docdir}/%{name}/*
 
 %changelog
+* Tue Mar 27 2012 Jaroslav Škarvada <jskarvad@redhat.com> - 3.4.0-1
+- New version
+- Fixed lockup on USRP1 r4.5 + DBSRX + another i2c board combo
+  (usrp1-r45-dbsrx-i2c-fix patch)
+  Resolves: rhbz#804440
+
 * Mon Mar 19 2012 Jaroslav Škarvada <jskarvad@redhat.com> - 3.3.2-1
 - New version