rma: enable WP on RMA disable

When RMA procedure is completed WP needs to be enabled back.

BRANCH=cr50, cr50-mp
BUG=b:37952913, b:73075443
TEST=on a Robo device, verified that WP is enabled, took the device
     through RMA unlock, verified that WP is disabled, took the device
     through RMA disable, verified that WP is enabled again.

     Also confirmed that after RMA is disabled WP status follows the
     battery.

Change-Id: Iad6af7d16aadcd10d580f709aeb942cf508a8489
Signed-off-by: Vadim Bendebury <vbendeb@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/905926
Reviewed-by: Randall Spangler <rspangler@chromium.org>

3 files changed, 31 insertions, 6 deletions

diff --git a/board/cr50/wp.c b/board/cr50/wp.c
index 63de13ed0b..41a676ff91 100644
--- a/board/cr50/wp.c
+++ b/board/cr50/wp.c
@@ -152,6 +152,18 @@ DECLARE_SAFE_CONSOLE_COMMAND(wp, command_wp,
 			     "[<BOOLEAN>/follow_batt_pres [atboot]]",
 			     "Get/set the flash HW write-protect signal");
 
+void set_wp_follow_ccd_config(void)
+{
+	if (ccd_get_flag(CCD_FLAG_OVERRIDE_WP_AT_BOOT)) {
+		/* Reset to at-boot state specified by CCD */
+		force_write_protect(1, ccd_get_flag
+				    (CCD_FLAG_OVERRIDE_WP_STATE_ENABLED));
+	} else {
+		/* Reset to WP based on battery-present (val is ignored) */
+		force_write_protect(0, 1);
+	}
+}
+
 void init_wp_state(void)
 {
 	/* Check system reset flags after CCD config is initially loaded */
@@ -170,13 +182,8 @@ void init_wp_state(void)
 			/* Write protected if battery is present */
 			set_wp_state(board_battery_is_present());
 		}
-	} else if (ccd_get_flag(CCD_FLAG_OVERRIDE_WP_AT_BOOT)) {
-		/* Reset to at-boot state specified by CCD */
-		force_write_protect(1, ccd_get_flag(
-		    CCD_FLAG_OVERRIDE_WP_STATE_ENABLED));
 	} else {
-		/* Reset to WP based on battery-present (val is ignored) */
-		force_write_protect(0, 1);
+		set_wp_follow_ccd_config();
 	}
 }
 
diff --git a/board/cr50/wp.h b/board/cr50/wp.h
index 6d93145ba6..35c02ae215 100644
--- a/board/cr50/wp.h
+++ b/board/cr50/wp.h
@@ -21,4 +21,9 @@ void init_wp_state(void);
  */
 void read_fwmp(void);
 
+/**
+ * Set WP as dicated by CCD configuration.
+ */
+void set_wp_follow_ccd_config(void);
+
 #endif  /* ! __EC_BOARD_CR50_WP_H */
diff --git a/common/ccd_config.c b/common/ccd_config.c
index 3e8165e97f..18b9aaa077 100644
--- a/common/ccd_config.c
+++ b/common/ccd_config.c
@@ -24,6 +24,7 @@
 #include "tpm_registers.h"
 #include "tpm_vendor_cmds.h"
 #include "trng.h"
+#include "wp.h"
 
 #define CPRINTS(format, args...) cprints(CC_CCD, format, ## args)
 #define CPRINTF(format, args...) cprintf(CC_CCD, format, ## args)
@@ -1530,6 +1531,7 @@ static enum vendor_cmd_rc ccd_disable_rma(enum vendor_cmd_cc code,
 	do {
 		if (raw_has_password()) {
 			error_line = __LINE__;
+			rv = EC_ERROR_ACCESS_DENIED;
 			break;
 		}
 
@@ -1571,6 +1573,17 @@ static enum vendor_cmd_rc ccd_disable_rma(enum vendor_cmd_cc code,
 
 
 		ccd_lock(NULL, 0, NULL);
+
+		/*
+		 * We do it here to make sure that the device comes out of RMA
+		 * with WP enabled, but in general CCD reset needs to enforce
+		 * WP state.
+		 *
+		 * TODO(rspangler): sort out CCD state and WP correlation,
+		 * b/73075443.
+		 */
+		set_wp_follow_ccd_config();
+
 		*response_size = 0;
 		return VENDOR_RC_SUCCESS;
 	} while (0);