linux-kernel - [PATCH] ipmi: handle run_to_completion properly in deliver_recv

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Date:	Tue, 25 May 2010 10:42:48 +0200 (CEST)
From:	Jiri Kosina <jkosina@...e.cz>
To:	Corey Minyard <minyard@....org>,
	Andrew Morton <akpm@...ux-foundation.org>
Cc:	linux-kernel@...r.kernel.org,
	openipmi-developer@...ts.sourceforge.net
Subject: [PATCH] ipmi: handle run_to_completion properly in
 deliver_recv_msg()

If run_to_completion flag is set, it means that we are running in
a single-threaded mode, and thus no locks are held.

This fixes a deadlock when IPMI notifier is being called during panic.

Signed-off-by: Jiri Kosina <jkosina@...e.cz>
---
 drivers/char/ipmi/ipmi_si_intf.c |   11 ++++++++---
 1 files changed, 8 insertions(+), 3 deletions(-)

diff --git a/drivers/char/ipmi/ipmi_si_intf.c b/drivers/char/ipmi/ipmi_si_intf.c
index 47ffe4a..d1765b6 100644
--- a/drivers/char/ipmi/ipmi_si_intf.c
+++ b/drivers/char/ipmi/ipmi_si_intf.c
@@ -314,9 +314,14 @@ static void deliver_recv_msg(struct smi_info *smi_info,
 {
 	/* Deliver the message to the upper layer with the lock
 	   released. */
-	spin_unlock(&(smi_info->si_lock));
-	ipmi_smi_msg_received(smi_info->intf, msg);
-	spin_lock(&(smi_info->si_lock));
+
+	if (smi_info->run_to_completion) {
+		ipmi_smi_msg_received(smi_info->intf, msg);
+	} else {
+		spin_unlock(&(smi_info->si_lock));
+		ipmi_smi_msg_received(smi_info->intf, msg);
+		spin_lock(&(smi_info->si_lock));
+	}
 }
 
 static void return_hosed_msg(struct smi_info *smi_info, int cCode)
-- 
1.6.4.2

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