use LINUX_TIFF_INSTALLED

xxxApp/src/Makefile

@@ -138,10 +138,12 @@ xxx_SYS_LIBS_vxWorks += -nil-
 
 # This is needed by areaDetector on Linux and WIN32
 xxx_LIBS_WIN32        += PvAPI
-# Couldn't get areaDetector to build on Linux with, e.g., libtiff.so.
-# Comment this out until we get libtiff.a installed, or solve the problem
-# some other way.  tmm
-#xxx_LIBS_Linux        += PvAPI
+
+ifeq ($(EPICS_HOST_ARCH), linux-x86)
+ifeq ($(LINUX_TIFF_INSTALLED), YES)
+xxx_LIBS_Linux        += PvAPI
+endif
+endif
 
 # This is needed by dxp on cygwin and WIN32
 xxx_SYS_LIBS_cygwin32 += DLPORTIO PlxApi setupapi