Only search through newly detected devices and discard ones that disappeared

diff --git a/tmk_core/avr.mk b/tmk_core/avr.mk
index 24722736ee9f1ed3662cc48f0790d79f0df6eda9..e11ba2e23e79a1a8f52cccf8e862b39b19d9e261 100644 (file)
--- a/tmk_core/avr.mk
+++ b/tmk_core/avr.mk
@@ -175,10 +175,11 @@ avrdude: $(BUILD_DIR)/$(TARGET).hex check-size
                ls /dev/tty* > /tmp/1; \
                echo -e "Detecting USB port, reset your controller now.\c"; \
                while [ -z $$USB ]; do \
-                       sleep 1; \
                        echo -e ".\c"; \
+                       sleep 0.5; \
                        ls /dev/tty* > /tmp/2; \
-                       USB=`diff /tmp/1 /tmp/2 | grep -o '/dev/tty.*'`; \
+                       USB=`comm -13 /tmp/1 /tmp/2 | grep -o '/dev/tty.*'`; \
+                       mv /tmp/2 /tmp/1; \
                done; \
                echo ""; \
                echo "Detected controller on USB port at $$USB"; \