[PATCH] ipmi: Add timeout to unconditional wait in __get_device_id()

[Matt Fleming <matt@readmodwrite.com>]

From: Matt Fleming <mfleming@cloudflare.com>

When the BMC does not respond to a "Get Device ID" command, the
wait_event() in __get_device_id() blocks forever in TASK_UNINTERRUPTIBLE
while holding bmc->dyn_mutex. Every subsequent sysfs reader then piles
up in D state. Replace with wait_event_timeout() to return -EIO after 1
second.

Signed-off-by: Matt Fleming <matt@readmodwrite.com>
---
 drivers/char/ipmi/ipmi_msghandler.c | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/drivers/char/ipmi/ipmi_msghandler.c b/drivers/char/ipmi/ipmi_msghandler.c
index c41f51c82edd..efa9588e8210 100644
--- a/drivers/char/ipmi/ipmi_msghandler.c
+++ b/drivers/char/ipmi/ipmi_msghandler.c
@@ -2599,7 +2599,13 @@ static int __get_device_id(struct ipmi_smi *intf, struct bmc_device *bmc)
 	if (rv)
 		goto out_reset_handler;
 
-	wait_event(intf->waitq, bmc->dyn_id_set != 2);
+	if (!wait_event_timeout(intf->waitq, bmc->dyn_id_set != 2,
+				msecs_to_jiffies(1000))) {
+		dev_warn(intf->si_dev,
+			 "Timed out waiting for get bmc device id response\n");
+		rv = -EIO;
+		goto out_reset_handler;
+	}
 
 	if (!bmc->dyn_id_set) {
 		if (bmc->cc != IPMI_CC_NO_ERROR &&
-- 
2.43.0