From: Frank Li <Frank.Li@freescale.com>
To: <lznuaa@gmail.com>, <davem@davemloft.net>,
<linux-arm-kernel@lists.infradead.org>, <netdev@vger.kernel.org>
Cc: <shawn.guo@linaro.org>, <B38611@freescale.com>,
<s.hauer@pengutronix.de>, Frank Li <Frank.Li@freescale.com>
Subject: [PATCH v3 2/2 net-next] net: fec: fix spin_lock dead lock
Date: Thu, 7 Feb 2013 08:59:59 +0800 [thread overview]
Message-ID: <1360198799-25173-2-git-send-email-Frank.Li@freescale.com> (raw)
In-Reply-To: <1360198799-25173-1-git-send-email-Frank.Li@freescale.com>
=========================================================
[ INFO: possible irq lock inversion dependency detected ]
3.8.0-rc5+ #82 Not tainted
---------------------------------------------------------
swapper/0/0 just changed the state of lock:
(&(&fep->hw_lock)->rlock){..-...}, at: [<8034e2f8>] fec_enet_start_xmit+0x48/0x 2cc
but this lock took another, SOFTIRQ-unsafe lock in the past:
(prepare_lock){+.+.+.}
and interrupts could create inverse lock ordering between them.
other info that might help us debug this:
Possible interrupt unsafe locking scenario:
CPU0 CPU1
---- ----
lock(prepare_lock);
local_irq_disable()
lock(&(&fep->hw_lock)->rlock);
lock(prepare_lock);
<Interrupt>
lock(&(&fep->hw_lock)->rlock);
*** DEADLOCK ***
Signed-off-by: Frank Li <Frank.Li@freescale.com>
---
No change from v1 to v3.
drivers/net/ethernet/freescale/fec_ptp.c | 4 +++-
1 files changed, 3 insertions(+), 1 deletions(-)
diff --git a/drivers/net/ethernet/freescale/fec_ptp.c b/drivers/net/ethernet/freescale/fec_ptp.c
index c40526c..1f17ca0 100644
--- a/drivers/net/ethernet/freescale/fec_ptp.c
+++ b/drivers/net/ethernet/freescale/fec_ptp.c
@@ -104,7 +104,7 @@ void fec_ptp_start_cyclecounter(struct net_device *ndev)
unsigned long flags;
int inc;
- inc = 1000000000 / clk_get_rate(fep->clk_ptp);
+ inc = 1000000000 / fep->cycle_speed;
/* grab the ptp lock */
spin_lock_irqsave(&fep->tmreg_lock, flags);
@@ -363,6 +363,8 @@ void fec_ptp_init(struct net_device *ndev, struct platform_device *pdev)
fep->ptp_caps.settime = fec_ptp_settime;
fep->ptp_caps.enable = fec_ptp_enable;
+ fep->cycle_speed = clk_get_rate(fep->clk_ptp);
+
spin_lock_init(&fep->tmreg_lock);
fec_ptp_start_cyclecounter(ndev);
--
1.7.1
WARNING: multiple messages have this Message-ID (diff)
From: Frank.Li@freescale.com (Frank Li)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH v3 2/2 net-next] net: fec: fix spin_lock dead lock
Date: Thu, 7 Feb 2013 08:59:59 +0800 [thread overview]
Message-ID: <1360198799-25173-2-git-send-email-Frank.Li@freescale.com> (raw)
In-Reply-To: <1360198799-25173-1-git-send-email-Frank.Li@freescale.com>
=========================================================
[ INFO: possible irq lock inversion dependency detected ]
3.8.0-rc5+ #82 Not tainted
---------------------------------------------------------
swapper/0/0 just changed the state of lock:
(&(&fep->hw_lock)->rlock){..-...}, at: [<8034e2f8>] fec_enet_start_xmit+0x48/0x 2cc
but this lock took another, SOFTIRQ-unsafe lock in the past:
(prepare_lock){+.+.+.}
and interrupts could create inverse lock ordering between them.
other info that might help us debug this:
Possible interrupt unsafe locking scenario:
CPU0 CPU1
---- ----
lock(prepare_lock);
local_irq_disable()
lock(&(&fep->hw_lock)->rlock);
lock(prepare_lock);
<Interrupt>
lock(&(&fep->hw_lock)->rlock);
*** DEADLOCK ***
Signed-off-by: Frank Li <Frank.Li@freescale.com>
---
No change from v1 to v3.
drivers/net/ethernet/freescale/fec_ptp.c | 4 +++-
1 files changed, 3 insertions(+), 1 deletions(-)
diff --git a/drivers/net/ethernet/freescale/fec_ptp.c b/drivers/net/ethernet/freescale/fec_ptp.c
index c40526c..1f17ca0 100644
--- a/drivers/net/ethernet/freescale/fec_ptp.c
+++ b/drivers/net/ethernet/freescale/fec_ptp.c
@@ -104,7 +104,7 @@ void fec_ptp_start_cyclecounter(struct net_device *ndev)
unsigned long flags;
int inc;
- inc = 1000000000 / clk_get_rate(fep->clk_ptp);
+ inc = 1000000000 / fep->cycle_speed;
/* grab the ptp lock */
spin_lock_irqsave(&fep->tmreg_lock, flags);
@@ -363,6 +363,8 @@ void fec_ptp_init(struct net_device *ndev, struct platform_device *pdev)
fep->ptp_caps.settime = fec_ptp_settime;
fep->ptp_caps.enable = fec_ptp_enable;
+ fep->cycle_speed = clk_get_rate(fep->clk_ptp);
+
spin_lock_init(&fep->tmreg_lock);
fec_ptp_start_cyclecounter(ndev);
--
1.7.1
next prev parent reply other threads:[~2013-02-07 1:37 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-02-07 0:59 [PATCH v3 1/2 net-next] net: fec: correct fix method about miss init spinlock Frank Li
2013-02-07 0:59 ` Frank Li
2013-02-07 0:59 ` Frank Li [this message]
2013-02-07 0:59 ` [PATCH v3 2/2 net-next] net: fec: fix spin_lock dead lock Frank Li
2013-02-08 4:37 ` David Miller
2013-02-08 4:37 ` David Miller
2013-02-08 4:36 ` [PATCH v3 1/2 net-next] net: fec: correct fix method about miss init spinlock David Miller
2013-02-08 4:36 ` David Miller
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