[PATCH v2 5/7] soc: microchip: mpfs: use a consistent completion timeout

From: Conor Dooley
Date: Fri Jan 20 2023 - 09:40:26 EST


Completion timeouts use jiffies, so passing a number directly will
produce inconsistent timeouts depending on config. Define the timeout in
ms and convert it to jiffies instead.

Since a define is being created where one previously did not exist,
pick a suitable timeout duration. Most services will complete nearly
immediately, but those relating to image verification and re-programming
the FPGA take significant amounts of time. 30 seconds is a suitable
timeout for those situations, although most services will complete in
under 100 ms.

Signed-off-by: Conor Dooley <conor.dooley@xxxxxxxxxxxxx>
---
drivers/soc/microchip/mpfs-sys-controller.c | 10 +++++++++-
1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/drivers/soc/microchip/mpfs-sys-controller.c b/drivers/soc/microchip/mpfs-sys-controller.c
index 12039cb38b33..e76a5e38f655 100644
--- a/drivers/soc/microchip/mpfs-sys-controller.c
+++ b/drivers/soc/microchip/mpfs-sys-controller.c
@@ -11,12 +11,19 @@
#include <linux/slab.h>
#include <linux/kref.h>
#include <linux/module.h>
+#include <linux/jiffies.h>
#include <linux/interrupt.h>
#include <linux/of_platform.h>
#include <linux/mailbox_client.h>
#include <linux/platform_device.h>
#include <soc/microchip/mpfs.h>

+/*
+ * This timeout must be long, as some services (example: image authentication)
+ * take many seconds to complete
+ */
+#define MPFS_SYS_CTRL_TIMEOUT_MS 30000
+
static DEFINE_MUTEX(transaction_lock);

struct mpfs_sys_controller {
@@ -28,6 +35,7 @@ struct mpfs_sys_controller {

int mpfs_blocking_transaction(struct mpfs_sys_controller *sys_controller, struct mpfs_mss_msg *msg)
{
+ unsigned long timeout = msecs_to_jiffies(MPFS_SYS_CTRL_TIMEOUT_MS);
int ret, err;

err = mutex_lock_interruptible(&transaction_lock);
@@ -38,7 +46,7 @@ int mpfs_blocking_transaction(struct mpfs_sys_controller *sys_controller, struct

ret = mbox_send_message(sys_controller->chan, msg);
if (ret >= 0) {
- if (wait_for_completion_timeout(&sys_controller->c, HZ)) {
+ if (wait_for_completion_timeout(&sys_controller->c, timeout)) {
ret = 0;
} else {
ret = -ETIMEDOUT;
--
2.39.0