From 4d7b6b5d247aa71ea27709b9eac1ba6e752fbe87 Mon Sep 17 00:00:00 2001
From: Ron Mercer <ron.mercer@qlogic.com>
Date: Sat, 11 Dec 2010 11:06:50 +0000
Subject: qlge: Fix deadlock when cancelling worker.

Removing usage of rtnl_lock() to protect firmware interface registers.
These registers are accessed in some worker threads and can create a
deadlock if rtnl_lock is taken by upper layers while the worker is still
pending.
We remove rtnl_lock and use a driver mutex just while mailboxes are
accessed.

Signed-off-by: Ron Mercer <ron.mercer@qlogic.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---
 drivers/net/qlge/qlge_mpi.c | 12 ++++--------
 1 file changed, 4 insertions(+), 8 deletions(-)

(limited to 'drivers/net/qlge/qlge_mpi.c')

diff --git a/drivers/net/qlge/qlge_mpi.c b/drivers/net/qlge/qlge_mpi.c
index 0e7c7c7ee164..a2e919bcb3c6 100644
--- a/drivers/net/qlge/qlge_mpi.c
+++ b/drivers/net/qlge/qlge_mpi.c
@@ -534,6 +534,7 @@ static int ql_mailbox_command(struct ql_adapter *qdev, struct mbox_params *mbcp)
 	int status;
 	unsigned long count;
 
+	mutex_lock(&qdev->mpi_mutex);
 
 	/* Begin polled mode for MPI */
 	ql_write32(qdev, INTR_MASK, (INTR_MASK_PI << 16));
@@ -603,6 +604,7 @@ done:
 end:
 	/* End polled mode for MPI */
 	ql_write32(qdev, INTR_MASK, (INTR_MASK_PI << 16) | INTR_MASK_PI);
+	mutex_unlock(&qdev->mpi_mutex);
 	return status;
 }
 
@@ -1099,9 +1101,7 @@ int ql_wait_fifo_empty(struct ql_adapter *qdev)
 static int ql_set_port_cfg(struct ql_adapter *qdev)
 {
 	int status;
-	rtnl_lock();
 	status = ql_mb_set_port_cfg(qdev);
-	rtnl_unlock();
 	if (status)
 		return status;
 	status = ql_idc_wait(qdev);
@@ -1122,9 +1122,7 @@ void ql_mpi_port_cfg_work(struct work_struct *work)
 	    container_of(work, struct ql_adapter, mpi_port_cfg_work.work);
 	int status;
 
-	rtnl_lock();
 	status = ql_mb_get_port_cfg(qdev);
-	rtnl_unlock();
 	if (status) {
 		netif_err(qdev, drv, qdev->ndev,
 			  "Bug: Failed to get port config data.\n");
@@ -1167,7 +1165,6 @@ void ql_mpi_idc_work(struct work_struct *work)
 	u32 aen;
 	int timeout;
 
-	rtnl_lock();
 	aen = mbcp->mbox_out[1] >> 16;
 	timeout = (mbcp->mbox_out[1] >> 8) & 0xf;
 
@@ -1231,7 +1228,6 @@ void ql_mpi_idc_work(struct work_struct *work)
 		}
 		break;
 	}
-	rtnl_unlock();
 }
 
 void ql_mpi_work(struct work_struct *work)
@@ -1242,7 +1238,7 @@ void ql_mpi_work(struct work_struct *work)
 	struct mbox_params *mbcp = &mbc;
 	int err = 0;
 
-	rtnl_lock();
+	mutex_lock(&qdev->mpi_mutex);
 	/* Begin polled mode for MPI */
 	ql_write32(qdev, INTR_MASK, (INTR_MASK_PI << 16));
 
@@ -1259,7 +1255,7 @@ void ql_mpi_work(struct work_struct *work)
 
 	/* End polled mode for MPI */
 	ql_write32(qdev, INTR_MASK, (INTR_MASK_PI << 16) | INTR_MASK_PI);
-	rtnl_unlock();
+	mutex_unlock(&qdev->mpi_mutex);
 	ql_enable_completion_interrupt(qdev, 0);
 }
 
-- 
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