commit 9765b27b5f39bb41a58edc893e7e8f2a0f1e20ef
author Patrick Shickel <pshickel@google.com> Fri Aug 16 14:20:18 2019 -0700
committer Patrick Shickel <pshickel@google.com> Fri Aug 16 14:23:40 2019 -0700
tree dfff775b7cfedfde73fb26d6f7207ba60d49d4c8
parent 642980e96916a8be053bc036ab4c2a88cce69b0a

[firmware] configure pull-up for serial UART RX pin

The serial UART RX pin was being (mis)configured such that it was floating when
the pin is not in use, which was leading to an IRQ storm. Resolved by
configuring an internal pull-up on this pin

Change-Id: I33707d94963ebeba8eaede3af2182b83b5e30e57

firmware/target/zedmon/init.c

diff --git a/firmware/target/zedmon/init.c b/firmware/target/zedmon/init.c
index a54021d..2c13057 100644
--- a/firmware/target/zedmon/init.c
+++ b/firmware/target/zedmon/init.c
@@ -54,7 +54,7 @@
 void target_early_init(void)
 {
     gpio_config(GPIO_UART_TX, GPIO_STM32_AF | GPIO_STM32_AFn(1));
-    gpio_config(GPIO_UART_RX, GPIO_STM32_AF | GPIO_STM32_AFn(1));
+    gpio_config(GPIO_UART_RX, GPIO_STM32_AF | GPIO_STM32_AFn(1) | GPIO_PULLUP);
 
     gpio_config(GPIO_SCL, GPIO_STM32_AF | GPIO_STM32_AFn(1));
     gpio_config(GPIO_SDA, GPIO_STM32_AF | GPIO_STM32_AFn(1));