arm/css/scpi: Don't panic if the SCP fails to respond
Instead, pass back the error to the calling function. This allows
platform code to fall back to another PSCI implementation if
scpi_wait_ready() or a later SCPI command fails.
Signed-off-by: Samuel Holland <samuel@sholland.org>
Change-Id: Ib4411e63c2512857f09ffffe1c405358dddeb4a6
diff --git a/drivers/arm/css/scpi/css_scpi.c b/drivers/arm/css/scpi/css_scpi.c
index c56b7c4..416356b 100644
--- a/drivers/arm/css/scpi/css_scpi.c
+++ b/drivers/arm/css/scpi/css_scpi.c
@@ -1,5 +1,5 @@
/*
- * Copyright (c) 2014-2018, ARM Limited and Contributors. All rights reserved.
+ * Copyright (c) 2014-2020, ARM Limited and Contributors. All rights reserved.
*
* SPDX-License-Identifier: BSD-3-Clause
*/
@@ -51,7 +51,7 @@
mhu_secure_message_send(SCPI_MHU_SLOT_ID);
}
-static void scpi_secure_message_receive(scpi_cmd_t *cmd)
+static int scpi_secure_message_receive(scpi_cmd_t *cmd)
{
uint32_t mhu_status;
@@ -63,7 +63,7 @@
if (mhu_status != (1 << SCPI_MHU_SLOT_ID)) {
ERROR("MHU: Unexpected protocol (MHU status: 0x%x)\n",
mhu_status);
- panic();
+ return -1;
}
/*
@@ -74,6 +74,8 @@
dmbld();
memcpy(cmd, (void *) SCPI_SHARED_MEM_SCP_TO_AP, sizeof(*cmd));
+
+ return 0;
}
static void scpi_secure_message_end(void)
@@ -84,14 +86,19 @@
int scpi_wait_ready(void)
{
scpi_cmd_t scpi_cmd;
+ int rc;
VERBOSE("Waiting for SCP_READY command...\n");
/* Get a message from the SCP */
scpi_secure_message_start();
- scpi_secure_message_receive(&scpi_cmd);
+ rc = scpi_secure_message_receive(&scpi_cmd);
scpi_secure_message_end();
+ /* If no message was received, don't send a response */
+ if (rc != 0)
+ return rc;
+
/* We are expecting 'SCP Ready', produce correct error if it's not */
scpi_status_t status = SCP_OK;
if (scpi_cmd.id != SCPI_CMD_SCP_READY) {
@@ -209,7 +216,8 @@
* Send message and wait for SCP's response
*/
scpi_secure_message_send(0);
- scpi_secure_message_receive(&response);
+ if (scpi_secure_message_receive(&response) != 0)
+ goto exit;
if (response.status != SCP_OK)
goto exit;
@@ -254,7 +262,9 @@
*payload_addr = system_state & 0xff;
scpi_secure_message_send(sizeof(*payload_addr));
- scpi_secure_message_receive(&response);
+ /* If no response is received, fill in an error status */
+ if (scpi_secure_message_receive(&response) != 0)
+ response.status = SCP_E_TIMEOUT;
scpi_secure_message_end();