cr50: Stop disabling the AP/EC uart when ccd is disabled

This change removes the uart disable in rdd_disconnect. It used to be
necessary because we used to disable device state detection in
rdd_disconnect. Without device state detect we had to disable the AP and
EC uart to make sure there were no interrupt storms. Now we keep device
state detection running all the time. It handles enabling/disabling the
AP and EC uart when it senses the RX signals aren't pulled up.

UART is only enabled/disabled when cr50 detects that the AP or EC state
changed from off to on or on to off. If the debug cable is detached and
then reattched the uart will be disabled on detach, but it won't be
reenabled until the AP/EC are rebooted.

BUG=chrome-os-partner:58222
BRANCH=none
TEST=Detach and reattach suzyq without rebooting the AP or EC and make
sure both consoles come back after reattaching the cable.

Change-Id: Id104e12dc533e8d7047f32aebd41abd1c959d267
Signed-off-by: Mary Ruthven <mruthven@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/410269
Reviewed-by: Bill Richardson <wfrichar@chromium.org>

1 files changed, 0 insertions, 4 deletions

diff --git a/board/cr50/rdd.c b/board/cr50/rdd.c
index 947808ede0..a9ed843f78 100644
--- a/board/cr50/rdd.c
+++ b/board/cr50/rdd.c
@@ -115,10 +115,6 @@ void rdd_detached(void)
 	uartn_tx_disconnect(UART_EC);
 	uartn_tx_disconnect(UART_AP);
 
-	/* Disable the AP and EC UART peripheral */
-	uartn_disable(UART_AP);
-	uartn_disable(UART_EC);
-
 	/* Done with case-closed debug mode */
 	gpio_set_level(GPIO_CCD_MODE_L, 1);