[PATCH 1/1] mmc: sdhci: fix lockdep error on tunning routine

[PATCH 1/1] mmc: sdhci: fix lockdep error on tunning routine

[Dong Aisheng]

The sdhci_execute_tuning routine gets lock separately by
disable_irq(host->irq);
spin_lock(&host->lock);
It will cause the following lockdep error message since the &host->lock
could also be got in irq context.
Use spin_lock_irqsave/spin_unlock_restore instead to get rid of
this error message.

[ INFO: inconsistent lock state ]
3.13.0-rc1+ #287 Not tainted
---------------------------------
inconsistent {IN-HARDIRQ-W} -> {HARDIRQ-ON-W} usage.
kworker/u2:1/33 [HC0[0]:SC0[0]:HE1:SE1] takes:
 (&(&host->lock)->rlock){?.-...}, at: [<8045f7f4>] sdhci_execute_tuning+0x4c/0x710
{IN-HARDIRQ-W} state was registered at:
  [<8005f030>] mark_lock+0x140/0x6ac
  [<80060760>] __lock_acquire+0xb30/0x1cbc
  [<800620d0>] lock_acquire+0x70/0x84
  [<8061d1c8>] _raw_spin_lock+0x30/0x40
  [<804605cc>] sdhci_irq+0x24/0xa68
  [<8006b1d4>] handle_irq_event_percpu+0x54/0x18c
  [<8006b350>] handle_irq_event+0x44/0x64
  [<8006e50c>] handle_fasteoi_irq+0xa0/0x170
  [<8006a8f0>] generic_handle_irq+0x30/0x44
  [<8000f238>] handle_IRQ+0x54/0xbc
  [<8000864c>] gic_handle_irq+0x30/0x64
  [<80013024>] __irq_svc+0x44/0x5c
  [<80329bf4>] dev_vprintk_emit+0x50/0x58
  [<80329c24>] dev_printk_emit+0x28/0x30
  [<80329fec>] __dev_printk+0x4c/0x90
  [<8032a180>] dev_err+0x3c/0x48
  [<802dd4f0>] _regulator_get+0x158/0x1cc
  [<802dd5b4>] regulator_get_optional+0x18/0x1c
  [<80461df4>] sdhci_add_host+0x42c/0xbd8
  [<80464820>] sdhci_esdhc_imx_probe+0x378/0x67c
  [<8032ee88>] platform_drv_probe+0x20/0x50
  [<8032d48c>] driver_probe_device+0x118/0x234
  [<8032d690>] __driver_attach+0x9c/0xa0
  [<8032b89c>] bus_for_each_dev+0x68/0x9c
  [<8032cf44>] driver_attach+0x20/0x28
  [<8032cbc8>] bus_add_driver+0x148/0x1f4
  [<8032dce0>] driver_register+0x80/0x100
  [<8032ee54>] __platform_driver_register+0x50/0x64
  [<8084b094>] sdhci_esdhc_imx_driver_init+0x18/0x20
  [<80008980>] do_one_initcall+0x108/0x16c
  [<8081cca4>] kernel_init_freeable+0x10c/0x1d0
  [<80611b28>] kernel_init+0x10/0x120
  [<8000e9c8>] ret_from_fork+0x14/0x2c
irq event stamp: 805
hardirqs last  enabled at (805): [<8061d43c>] _raw_spin_unlock_irqrestore+0x38/0x4c
hardirqs last disabled at (804): [<8061d2c8>] _raw_spin_lock_irqsave+0x24/0x54
softirqs last  enabled at (570): [<8002b824>] __do_softirq+0x1c4/0x290
softirqs last disabled at (561): [<8002bcf4>] irq_exit+0xb4/0x10c

other info that might help us debug this:
 Possible unsafe locking scenario:

       CPU0
       ----
  lock(&(&host->lock)->rlock);
  <Interrupt>
    lock(&(&host->lock)->rlock);

 *** DEADLOCK ***

2 locks held by kworker/u2:1/33:
 #0:  (kmmcd){.+.+..}, at: [<8003db18>] process_one_work+0x128/0x468
 #1:  ((&(&host->detect)->work)){+.+...}, at: [<8003db18>] process_one_work+0x128/0x468

stack backtrace:
CPU: 0 PID: 33 Comm: kworker/u2:1 Not tainted 3.13.0-rc1+ #287
Workqueue: kmmcd mmc_rescan
Backtrace:
[<80012160>] (dump_backtrace+0x0/0x10c) from [<80012438>] (show_stack+0x18/0x1c)
 r6:bfad0900 r5:00000000 r4:8088ecc8 r3:bfad0900
[<80012420>] (show_stack+0x0/0x1c) from [<806169ec>] (dump_stack+0x84/0x9c)
[<80616968>] (dump_stack+0x0/0x9c) from [<806147b4>] (print_usage_bug+0x260/0x2d0)
 r5:8076ba88 r4:80977410
[<80614554>] (print_usage_bug+0x0/0x2d0) from [<8005f0d0>] (mark_lock+0x1e0/0x6ac)
 r9:8005e678 r8:00000000 r7:bfad0900 r6:00001015 r5:bfad0cd0
r4:00000002
[<8005eef0>] (mark_lock+0x0/0x6ac) from [<80060234>] (__lock_acquire+0x604/0x1cbc)
[<8005fc30>] (__lock_acquire+0x0/0x1cbc) from [<800620d0>] (lock_acquire+0x70/0x84)
[<80062060>] (lock_acquire+0x0/0x84) from [<8061d1c8>] (_raw_spin_lock+0x30/0x40)
 r7:00000000 r6:bfb63000 r5:00000000 r4:bfb60568
[<8061d198>] (_raw_spin_lock+0x0/0x40) from [<8045f7f4>] (sdhci_execute_tuning+0x4c/0x710)
 r4:bfb60000
[<8045f7a8>] (sdhci_execute_tuning+0x0/0x710) from [<80453454>] (mmc_sd_init_card+0x5f8/0x660)
[<80452e5c>] (mmc_sd_init_card+0x0/0x660) from [<80453748>] (mmc_attach_sd+0xb4/0x180)
 r9:bf92d400 r8:8065f364 r7:00061a80 r6:bfb60000 r5:8065f358
r4:bfb60000
[<80453694>] (mmc_attach_sd+0x0/0x180) from [<8044d9f8>] (mmc_rescan+0x284/0x2f0)
 r5:8065f358 r4:bfb602f8
[<8044d774>] (mmc_rescan+0x0/0x2f0) from [<8003db94>] (process_one_work+0x1a4/0x468)
 r8:00000000 r7:bfb55eb0 r6:bf80dc00 r5:bfb602f8 r4:bfb35980
r3:8044d774
[<8003d9f0>] (process_one_work+0x0/0x468) from [<8003e850>] (worker_thread+0x118/0x3e0)
[<8003e738>] (worker_thread+0x0/0x3e0) from [<80044de0>] (kthread+0xd4/0xf0)
[<80044d0c>] (kthread+0x0/0xf0) from [<8000e9c8>] (ret_from_fork+0x14/0x2c)
 r7:00000000 r6:00000000 r5:80044d0c r4:bfb37b40

Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Chris Ball <cjb@laptop.org>
Cc: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Dong Aisheng <b29396@freescale.com>

---
It's strange that this issue did not happen on kernel 3.10.17 with the same
code. And looking at the code, before call spin_lock we already disable the mmc
controller irq, per on my understanding, the deadlock given by lockdep may not
be able to happen(pls fix me if wrong).
May the lockdep not track the specific irq disable?
Copy lockdep guy to comment.
---
 drivers/mmc/host/sdhci.c |   20 +++++++-------------
 1 files changed, 7 insertions(+), 13 deletions(-)

diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
index a104bb1..c5d5f53 100644
--- a/drivers/mmc/host/sdhci.c
+++ b/drivers/mmc/host/sdhci.c
@@ -1876,12 +1876,12 @@ static int sdhci_execute_tuning(struct mmc_host *mmc, u32 opcode)
 	unsigned long timeout;
 	int err = 0;
 	bool requires_tuning_nonuhs = false;
+	unsigned long flags;
 
 	host = mmc_priv(mmc);
 
 	sdhci_runtime_pm_get(host);
-	disable_irq(host->irq);
-	spin_lock(&host->lock);
+	spin_lock_irqsave(&host->lock, flags);
 
 	ctrl = sdhci_readw(host, SDHCI_HOST_CONTROL2);
 
@@ -1901,15 +1901,13 @@ static int sdhci_execute_tuning(struct mmc_host *mmc, u32 opcode)
 	    requires_tuning_nonuhs)
 		ctrl |= SDHCI_CTRL_EXEC_TUNING;
 	else {
-		spin_unlock(&host->lock);
-		enable_irq(host->irq);
+		spin_unlock_irqrestore(&host->lock, flags);
 		sdhci_runtime_pm_put(host);
 		return 0;
 	}
 
 	if (host->ops->platform_execute_tuning) {
-		spin_unlock(&host->lock);
-		enable_irq(host->irq);
+		spin_unlock_irqrestore(&host->lock, flags);
 		err = host->ops->platform_execute_tuning(host, opcode);
 		sdhci_runtime_pm_put(host);
 		return err;
@@ -1982,15 +1980,12 @@ static int sdhci_execute_tuning(struct mmc_host *mmc, u32 opcode)
 		host->cmd = NULL;
 		host->mrq = NULL;
 
-		spin_unlock(&host->lock);
-		enable_irq(host->irq);
-
+		spin_unlock_irqrestore(&host->lock, flags);
 		/* Wait for Buffer Read Ready interrupt */
 		wait_event_interruptible_timeout(host->buf_ready_int,
 					(host->tuning_done == 1),
 					msecs_to_jiffies(50));
-		disable_irq(host->irq);
-		spin_lock(&host->lock);
+		spin_lock_irqsave(&host->lock, flags);
 
 		if (!host->tuning_done) {
 			pr_info(DRIVER_NAME ": Timeout waiting for "
@@ -2065,8 +2060,7 @@ out:
 		err = 0;
 
 	sdhci_clear_set_irqs(host, SDHCI_INT_DATA_AVAIL, ier);
-	spin_unlock(&host->lock);
-	enable_irq(host->irq);
+	spin_unlock_irqrestore(&host->lock, flags);
 	sdhci_runtime_pm_put(host);
 
 	return err;
-- 
1.7.2.rc3

[PATCH 1/1] mmc: sdhci: fix lockdep error on tunning routine

[Dong Aisheng]

The sdhci_execute_tuning routine gets lock separately by
disable_irq(host->irq);
spin_lock(&host->lock);
It will cause the following lockdep error message since the &host->lock
could also be got in irq context.
Use spin_lock_irqsave/spin_unlock_restore instead to get rid of
this error message.

[ INFO: inconsistent lock state ]
3.13.0-rc1+ #287 Not tainted
---------------------------------
inconsistent {IN-HARDIRQ-W} -> {HARDIRQ-ON-W} usage.
kworker/u2:1/33 [HC0[0]:SC0[0]:HE1:SE1] takes:
 (&(&host->lock)->rlock){?.-...}, at: [<8045f7f4>] sdhci_execute_tuning+0x4c/0x710
{IN-HARDIRQ-W} state was registered at:
  [<8005f030>] mark_lock+0x140/0x6ac
  [<80060760>] __lock_acquire+0xb30/0x1cbc
  [<800620d0>] lock_acquire+0x70/0x84
  [<8061d1c8>] _raw_spin_lock+0x30/0x40
  [<804605cc>] sdhci_irq+0x24/0xa68
  [<8006b1d4>] handle_irq_event_percpu+0x54/0x18c
  [<8006b350>] handle_irq_event+0x44/0x64
  [<8006e50c>] handle_fasteoi_irq+0xa0/0x170
  [<8006a8f0>] generic_handle_irq+0x30/0x44
  [<8000f238>] handle_IRQ+0x54/0xbc
  [<8000864c>] gic_handle_irq+0x30/0x64
  [<80013024>] __irq_svc+0x44/0x5c
  [<80329bf4>] dev_vprintk_emit+0x50/0x58
  [<80329c24>] dev_printk_emit+0x28/0x30
  [<80329fec>] __dev_printk+0x4c/0x90
  [<8032a180>] dev_err+0x3c/0x48
  [<802dd4f0>] _regulator_get+0x158/0x1cc
  [<802dd5b4>] regulator_get_optional+0x18/0x1c
  [<80461df4>] sdhci_add_host+0x42c/0xbd8
  [<80464820>] sdhci_esdhc_imx_probe+0x378/0x67c
  [<8032ee88>] platform_drv_probe+0x20/0x50
  [<8032d48c>] driver_probe_device+0x118/0x234
  [<8032d690>] __driver_attach+0x9c/0xa0
  [<8032b89c>] bus_for_each_dev+0x68/0x9c
  [<8032cf44>] driver_attach+0x20/0x28
  [<8032cbc8>] bus_add_driver+0x148/0x1f4
  [<8032dce0>] driver_register+0x80/0x100
  [<8032ee54>] __platform_driver_register+0x50/0x64
  [<8084b094>] sdhci_esdhc_imx_driver_init+0x18/0x20
  [<80008980>] do_one_initcall+0x108/0x16c
  [<8081cca4>] kernel_init_freeable+0x10c/0x1d0
  [<80611b28>] kernel_init+0x10/0x120
  [<8000e9c8>] ret_from_fork+0x14/0x2c
irq event stamp: 805
hardirqs last  enabled at (805): [<8061d43c>] _raw_spin_unlock_irqrestore+0x38/0x4c
hardirqs last disabled at (804): [<8061d2c8>] _raw_spin_lock_irqsave+0x24/0x54
softirqs last  enabled at (570): [<8002b824>] __do_softirq+0x1c4/0x290
softirqs last disabled at (561): [<8002bcf4>] irq_exit+0xb4/0x10c

other info that might help us debug this:
 Possible unsafe locking scenario:

       CPU0
       ----
  lock(&(&host->lock)->rlock);
  <Interrupt>
    lock(&(&host->lock)->rlock);

 *** DEADLOCK ***

2 locks held by kworker/u2:1/33:
 #0:  (kmmcd){.+.+..}, at: [<8003db18>] process_one_work+0x128/0x468
 #1:  ((&(&host->detect)->work)){+.+...}, at: [<8003db18>] process_one_work+0x128/0x468

stack backtrace:
CPU: 0 PID: 33 Comm: kworker/u2:1 Not tainted 3.13.0-rc1+ #287
Workqueue: kmmcd mmc_rescan
Backtrace:
[<80012160>] (dump_backtrace+0x0/0x10c) from [<80012438>] (show_stack+0x18/0x1c)
 r6:bfad0900 r5:00000000 r4:8088ecc8 r3:bfad0900
[<80012420>] (show_stack+0x0/0x1c) from [<806169ec>] (dump_stack+0x84/0x9c)
[<80616968>] (dump_stack+0x0/0x9c) from [<806147b4>] (print_usage_bug+0x260/0x2d0)
 r5:8076ba88 r4:80977410
[<80614554>] (print_usage_bug+0x0/0x2d0) from [<8005f0d0>] (mark_lock+0x1e0/0x6ac)
 r9:8005e678 r8:00000000 r7:bfad0900 r6:00001015 r5:bfad0cd0
r4:00000002
[<8005eef0>] (mark_lock+0x0/0x6ac) from [<80060234>] (__lock_acquire+0x604/0x1cbc)
[<8005fc30>] (__lock_acquire+0x0/0x1cbc) from [<800620d0>] (lock_acquire+0x70/0x84)
[<80062060>] (lock_acquire+0x0/0x84) from [<8061d1c8>] (_raw_spin_lock+0x30/0x40)
 r7:00000000 r6:bfb63000 r5:00000000 r4:bfb60568
[<8061d198>] (_raw_spin_lock+0x0/0x40) from [<8045f7f4>] (sdhci_execute_tuning+0x4c/0x710)
 r4:bfb60000
[<8045f7a8>] (sdhci_execute_tuning+0x0/0x710) from [<80453454>] (mmc_sd_init_card+0x5f8/0x660)
[<80452e5c>] (mmc_sd_init_card+0x0/0x660) from [<80453748>] (mmc_attach_sd+0xb4/0x180)
 r9:bf92d400 r8:8065f364 r7:00061a80 r6:bfb60000 r5:8065f358
r4:bfb60000
[<80453694>] (mmc_attach_sd+0x0/0x180) from [<8044d9f8>] (mmc_rescan+0x284/0x2f0)
 r5:8065f358 r4:bfb602f8
[<8044d774>] (mmc_rescan+0x0/0x2f0) from [<8003db94>] (process_one_work+0x1a4/0x468)
 r8:00000000 r7:bfb55eb0 r6:bf80dc00 r5:bfb602f8 r4:bfb35980
r3:8044d774
[<8003d9f0>] (process_one_work+0x0/0x468) from [<8003e850>] (worker_thread+0x118/0x3e0)
[<8003e738>] (worker_thread+0x0/0x3e0) from [<80044de0>] (kthread+0xd4/0xf0)
[<80044d0c>] (kthread+0x0/0xf0) from [<8000e9c8>] (ret_from_fork+0x14/0x2c)
 r7:00000000 r6:00000000 r5:80044d0c r4:bfb37b40

Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Chris Ball <cjb@laptop.org>
Cc: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Dong Aisheng <b29396@freescale.com>

---
It's strange that this issue did not happen on kernel 3.10.17 with the same
code. And looking at the code, before call spin_lock we already disable the mmc
controller irq, per on my understanding, the deadlock given by lockdep may not
be able to happen(pls fix me if wrong).
May the lockdep not track the specific irq disable?
Copy lockdep guy to comment.
---
 drivers/mmc/host/sdhci.c |   20 +++++++-------------
 1 files changed, 7 insertions(+), 13 deletions(-)

diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
index a104bb1..c5d5f53 100644
--- a/drivers/mmc/host/sdhci.c
+++ b/drivers/mmc/host/sdhci.c
@@ -1876,12 +1876,12 @@ static int sdhci_execute_tuning(struct mmc_host *mmc, u32 opcode)
 	unsigned long timeout;
 	int err = 0;
 	bool requires_tuning_nonuhs = false;
+	unsigned long flags;
 
 	host = mmc_priv(mmc);
 
 	sdhci_runtime_pm_get(host);
-	disable_irq(host->irq);
-	spin_lock(&host->lock);
+	spin_lock_irqsave(&host->lock, flags);
 
 	ctrl = sdhci_readw(host, SDHCI_HOST_CONTROL2);
 
@@ -1901,15 +1901,13 @@ static int sdhci_execute_tuning(struct mmc_host *mmc, u32 opcode)
 	    requires_tuning_nonuhs)
 		ctrl |= SDHCI_CTRL_EXEC_TUNING;
 	else {
-		spin_unlock(&host->lock);
-		enable_irq(host->irq);
+		spin_unlock_irqrestore(&host->lock, flags);
 		sdhci_runtime_pm_put(host);
 		return 0;
 	}
 
 	if (host->ops->platform_execute_tuning) {
-		spin_unlock(&host->lock);
-		enable_irq(host->irq);
+		spin_unlock_irqrestore(&host->lock, flags);
 		err = host->ops->platform_execute_tuning(host, opcode);
 		sdhci_runtime_pm_put(host);
 		return err;
@@ -1982,15 +1980,12 @@ static int sdhci_execute_tuning(struct mmc_host *mmc, u32 opcode)
 		host->cmd = NULL;
 		host->mrq = NULL;
 
-		spin_unlock(&host->lock);
-		enable_irq(host->irq);
-
+		spin_unlock_irqrestore(&host->lock, flags);
 		/* Wait for Buffer Read Ready interrupt */
 		wait_event_interruptible_timeout(host->buf_ready_int,
 					(host->tuning_done == 1),
 					msecs_to_jiffies(50));
-		disable_irq(host->irq);
-		spin_lock(&host->lock);
+		spin_lock_irqsave(&host->lock, flags);
 
 		if (!host->tuning_done) {
 			pr_info(DRIVER_NAME ": Timeout waiting for "
@@ -2065,8 +2060,7 @@ out:
 		err = 0;
 
 	sdhci_clear_set_irqs(host, SDHCI_INT_DATA_AVAIL, ier);
-	spin_unlock(&host->lock);
-	enable_irq(host->irq);
+	spin_unlock_irqrestore(&host->lock, flags);
 	sdhci_runtime_pm_put(host);
 
 	return err;
-- 
1.7.2.rc3

Re: [PATCH 1/1] mmc: sdhci: fix lockdep error on tunning routine

[Shawn Guo]

On Mon, Dec 23, 2013 at 07:13:04PM +0800, Dong Aisheng wrote:
> It's strange that this issue did not happen on kernel 3.10.17 with the same
> code.

Probably just because you did not turn on CONFIG_PROVE_LOCKING on your
3.10.17 kennel.

Shawn

> And looking at the code, before call spin_lock we already disable the mmc
> controller irq, per on my understanding, the deadlock given by lockdep may not
> be able to happen(pls fix me if wrong).
> May the lockdep not track the specific irq disable?
> Copy lockdep guy to comment.
> ---

[PATCH 1/1] mmc: sdhci: fix lockdep error on tunning routine

[Shawn Guo]

On Mon, Dec 23, 2013 at 07:13:04PM +0800, Dong Aisheng wrote:
> It's strange that this issue did not happen on kernel 3.10.17 with the same
> code.

Probably just because you did not turn on CONFIG_PROVE_LOCKING on your
3.10.17 kennel.

Shawn

> And looking at the code, before call spin_lock we already disable the mmc
> controller irq, per on my understanding, the deadlock given by lockdep may not
> be able to happen(pls fix me if wrong).
> May the lockdep not track the specific irq disable?
> Copy lockdep guy to comment.
> ---

Re: [PATCH 1/1] mmc: sdhci: fix lockdep error on tunning routine

[Dong Aisheng]

On Mon, Dec 23, 2013 at 08:23:17PM +0800, Shawn Guo wrote:
> On Mon, Dec 23, 2013 at 07:13:04PM +0800, Dong Aisheng wrote:
> > It's strange that this issue did not happen on kernel 3.10.17 with the same
> > code.
> 
> Probably just because you did not turn on CONFIG_PROVE_LOCKING on your
> 3.10.17 kennel.
> 

I did turn it on for the test.

Regards
Dong Aisheng

> Shawn
> 
> > And looking at the code, before call spin_lock we already disable the mmc
> > controller irq, per on my understanding, the deadlock given by lockdep may not
> > be able to happen(pls fix me if wrong).
> > May the lockdep not track the specific irq disable?
> > Copy lockdep guy to comment.
> > ---
> 

[PATCH 1/1] mmc: sdhci: fix lockdep error on tunning routine

[Dong Aisheng]

On Mon, Dec 23, 2013 at 08:23:17PM +0800, Shawn Guo wrote:
> On Mon, Dec 23, 2013 at 07:13:04PM +0800, Dong Aisheng wrote:
> > It's strange that this issue did not happen on kernel 3.10.17 with the same
> > code.
> 
> Probably just because you did not turn on CONFIG_PROVE_LOCKING on your
> 3.10.17 kennel.
> 

I did turn it on for the test.

Regards
Dong Aisheng

> Shawn
> 
> > And looking at the code, before call spin_lock we already disable the mmc
> > controller irq, per on my understanding, the deadlock given by lockdep may not
> > be able to happen(pls fix me if wrong).
> > May the lockdep not track the specific irq disable?
> > Copy lockdep guy to comment.
> > ---
> 

Re: [PATCH 1/1] mmc: sdhci: fix lockdep error on tunning routine

[Dong Aisheng]

Hi Peter,

On Mon, Dec 23, 2013 at 7:13 PM, Dong Aisheng <b29396@freescale.com> wrote:
> The sdhci_execute_tuning routine gets lock separately by
> disable_irq(host->irq);
> spin_lock(&host->lock);
> It will cause the following lockdep error message since the &host->lock
> could also be got in irq context.
> Use spin_lock_irqsave/spin_unlock_restore instead to get rid of
> this error message.
>
> [ INFO: inconsistent lock state ]
> 3.13.0-rc1+ #287 Not tainted
> ---------------------------------
> inconsistent {IN-HARDIRQ-W} -> {HARDIRQ-ON-W} usage.
> kworker/u2:1/33 [HC0[0]:SC0[0]:HE1:SE1] takes:
>  (&(&host->lock)->rlock){?.-...}, at: [<8045f7f4>] sdhci_execute_tuning+0x4c/0x710
> {IN-HARDIRQ-W} state was registered at:
>   [<8005f030>] mark_lock+0x140/0x6ac
>   [<80060760>] __lock_acquire+0xb30/0x1cbc
>   [<800620d0>] lock_acquire+0x70/0x84
>   [<8061d1c8>] _raw_spin_lock+0x30/0x40
>   [<804605cc>] sdhci_irq+0x24/0xa68
>   [<8006b1d4>] handle_irq_event_percpu+0x54/0x18c
>   [<8006b350>] handle_irq_event+0x44/0x64
>   [<8006e50c>] handle_fasteoi_irq+0xa0/0x170
>   [<8006a8f0>] generic_handle_irq+0x30/0x44
>   [<8000f238>] handle_IRQ+0x54/0xbc
>   [<8000864c>] gic_handle_irq+0x30/0x64
>   [<80013024>] __irq_svc+0x44/0x5c
>   [<80329bf4>] dev_vprintk_emit+0x50/0x58
>   [<80329c24>] dev_printk_emit+0x28/0x30
>   [<80329fec>] __dev_printk+0x4c/0x90
>   [<8032a180>] dev_err+0x3c/0x48
>   [<802dd4f0>] _regulator_get+0x158/0x1cc
>   [<802dd5b4>] regulator_get_optional+0x18/0x1c
>   [<80461df4>] sdhci_add_host+0x42c/0xbd8
>   [<80464820>] sdhci_esdhc_imx_probe+0x378/0x67c
>   [<8032ee88>] platform_drv_probe+0x20/0x50
>   [<8032d48c>] driver_probe_device+0x118/0x234
>   [<8032d690>] __driver_attach+0x9c/0xa0
>   [<8032b89c>] bus_for_each_dev+0x68/0x9c
>   [<8032cf44>] driver_attach+0x20/0x28
>   [<8032cbc8>] bus_add_driver+0x148/0x1f4
>   [<8032dce0>] driver_register+0x80/0x100
>   [<8032ee54>] __platform_driver_register+0x50/0x64
>   [<8084b094>] sdhci_esdhc_imx_driver_init+0x18/0x20
>   [<80008980>] do_one_initcall+0x108/0x16c
>   [<8081cca4>] kernel_init_freeable+0x10c/0x1d0
>   [<80611b28>] kernel_init+0x10/0x120
>   [<8000e9c8>] ret_from_fork+0x14/0x2c
> irq event stamp: 805
> hardirqs last  enabled at (805): [<8061d43c>] _raw_spin_unlock_irqrestore+0x38/0x4c
> hardirqs last disabled at (804): [<8061d2c8>] _raw_spin_lock_irqsave+0x24/0x54
> softirqs last  enabled at (570): [<8002b824>] __do_softirq+0x1c4/0x290
> softirqs last disabled at (561): [<8002bcf4>] irq_exit+0xb4/0x10c
>
> other info that might help us debug this:
>  Possible unsafe locking scenario:
>
>        CPU0
>        ----
>   lock(&(&host->lock)->rlock);
>   <Interrupt>
>     lock(&(&host->lock)->rlock);
>
>  *** DEADLOCK ***
>
> 2 locks held by kworker/u2:1/33:
>  #0:  (kmmcd){.+.+..}, at: [<8003db18>] process_one_work+0x128/0x468
>  #1:  ((&(&host->detect)->work)){+.+...}, at: [<8003db18>] process_one_work+0x128/0x468
>
> stack backtrace:
> CPU: 0 PID: 33 Comm: kworker/u2:1 Not tainted 3.13.0-rc1+ #287
> Workqueue: kmmcd mmc_rescan
> Backtrace:
> [<80012160>] (dump_backtrace+0x0/0x10c) from [<80012438>] (show_stack+0x18/0x1c)
>  r6:bfad0900 r5:00000000 r4:8088ecc8 r3:bfad0900
> [<80012420>] (show_stack+0x0/0x1c) from [<806169ec>] (dump_stack+0x84/0x9c)
> [<80616968>] (dump_stack+0x0/0x9c) from [<806147b4>] (print_usage_bug+0x260/0x2d0)
>  r5:8076ba88 r4:80977410
> [<80614554>] (print_usage_bug+0x0/0x2d0) from [<8005f0d0>] (mark_lock+0x1e0/0x6ac)
>  r9:8005e678 r8:00000000 r7:bfad0900 r6:00001015 r5:bfad0cd0
> r4:00000002
> [<8005eef0>] (mark_lock+0x0/0x6ac) from [<80060234>] (__lock_acquire+0x604/0x1cbc)
> [<8005fc30>] (__lock_acquire+0x0/0x1cbc) from [<800620d0>] (lock_acquire+0x70/0x84)
> [<80062060>] (lock_acquire+0x0/0x84) from [<8061d1c8>] (_raw_spin_lock+0x30/0x40)
>  r7:00000000 r6:bfb63000 r5:00000000 r4:bfb60568
> [<8061d198>] (_raw_spin_lock+0x0/0x40) from [<8045f7f4>] (sdhci_execute_tuning+0x4c/0x710)
>  r4:bfb60000
> [<8045f7a8>] (sdhci_execute_tuning+0x0/0x710) from [<80453454>] (mmc_sd_init_card+0x5f8/0x660)
> [<80452e5c>] (mmc_sd_init_card+0x0/0x660) from [<80453748>] (mmc_attach_sd+0xb4/0x180)
>  r9:bf92d400 r8:8065f364 r7:00061a80 r6:bfb60000 r5:8065f358
> r4:bfb60000
> [<80453694>] (mmc_attach_sd+0x0/0x180) from [<8044d9f8>] (mmc_rescan+0x284/0x2f0)
>  r5:8065f358 r4:bfb602f8
> [<8044d774>] (mmc_rescan+0x0/0x2f0) from [<8003db94>] (process_one_work+0x1a4/0x468)
>  r8:00000000 r7:bfb55eb0 r6:bf80dc00 r5:bfb602f8 r4:bfb35980
> r3:8044d774
> [<8003d9f0>] (process_one_work+0x0/0x468) from [<8003e850>] (worker_thread+0x118/0x3e0)
> [<8003e738>] (worker_thread+0x0/0x3e0) from [<80044de0>] (kthread+0xd4/0xf0)
> [<80044d0c>] (kthread+0x0/0xf0) from [<8000e9c8>] (ret_from_fork+0x14/0x2c)
>  r7:00000000 r6:00000000 r5:80044d0c r4:bfb37b40
>
> Cc: Peter Zijlstra <peterz@infradead.org>
> Cc: Chris Ball <cjb@laptop.org>
> Cc: Shawn Guo <shawn.guo@linaro.org>
> Signed-off-by: Dong Aisheng <b29396@freescale.com>
>
> ---
> It's strange that this issue did not happen on kernel 3.10.17 with the same
> code. And looking at the code, before call spin_lock we already disable the mmc
> controller irq, per on my understanding, the deadlock given by lockdep may not
> be able to happen(pls fix me if wrong).
> May the lockdep not track the specific irq disable?
> Copy lockdep guy to comment.

Any comments for it?

Regards
Dong Aisheng

> ---
>  drivers/mmc/host/sdhci.c |   20 +++++++-------------
>  1 files changed, 7 insertions(+), 13 deletions(-)
>
> diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
> index a104bb1..c5d5f53 100644
> --- a/drivers/mmc/host/sdhci.c
> +++ b/drivers/mmc/host/sdhci.c
> @@ -1876,12 +1876,12 @@ static int sdhci_execute_tuning(struct mmc_host *mmc, u32 opcode)
>         unsigned long timeout;
>         int err = 0;
>         bool requires_tuning_nonuhs = false;
> +       unsigned long flags;
>
>         host = mmc_priv(mmc);
>
>         sdhci_runtime_pm_get(host);
> -       disable_irq(host->irq);
> -       spin_lock(&host->lock);
> +       spin_lock_irqsave(&host->lock, flags);
>
>         ctrl = sdhci_readw(host, SDHCI_HOST_CONTROL2);
>
> @@ -1901,15 +1901,13 @@ static int sdhci_execute_tuning(struct mmc_host *mmc, u32 opcode)
>             requires_tuning_nonuhs)
>                 ctrl |= SDHCI_CTRL_EXEC_TUNING;
>         else {
> -               spin_unlock(&host->lock);
> -               enable_irq(host->irq);
> +               spin_unlock_irqrestore(&host->lock, flags);
>                 sdhci_runtime_pm_put(host);
>                 return 0;
>         }
>
>         if (host->ops->platform_execute_tuning) {
> -               spin_unlock(&host->lock);
> -               enable_irq(host->irq);
> +               spin_unlock_irqrestore(&host->lock, flags);
>                 err = host->ops->platform_execute_tuning(host, opcode);
>                 sdhci_runtime_pm_put(host);
>                 return err;
> @@ -1982,15 +1980,12 @@ static int sdhci_execute_tuning(struct mmc_host *mmc, u32 opcode)
>                 host->cmd = NULL;
>                 host->mrq = NULL;
>
> -               spin_unlock(&host->lock);
> -               enable_irq(host->irq);
> -
> +               spin_unlock_irqrestore(&host->lock, flags);
>                 /* Wait for Buffer Read Ready interrupt */
>                 wait_event_interruptible_timeout(host->buf_ready_int,
>                                         (host->tuning_done == 1),
>                                         msecs_to_jiffies(50));
> -               disable_irq(host->irq);
> -               spin_lock(&host->lock);
> +               spin_lock_irqsave(&host->lock, flags);
>
>                 if (!host->tuning_done) {
>                         pr_info(DRIVER_NAME ": Timeout waiting for "
> @@ -2065,8 +2060,7 @@ out:
>                 err = 0;
>
>         sdhci_clear_set_irqs(host, SDHCI_INT_DATA_AVAIL, ier);
> -       spin_unlock(&host->lock);
> -       enable_irq(host->irq);
> +       spin_unlock_irqrestore(&host->lock, flags);
>         sdhci_runtime_pm_put(host);
>
>         return err;
> --
> 1.7.2.rc3
>
>
>
> _______________________________________________
> linux-arm-kernel mailing list
> linux-arm-kernel@lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

[PATCH 1/1] mmc: sdhci: fix lockdep error on tunning routine

[Dong Aisheng]

Hi Peter,

On Mon, Dec 23, 2013 at 7:13 PM, Dong Aisheng <b29396@freescale.com> wrote:
> The sdhci_execute_tuning routine gets lock separately by
> disable_irq(host->irq);
> spin_lock(&host->lock);
> It will cause the following lockdep error message since the &host->lock
> could also be got in irq context.
> Use spin_lock_irqsave/spin_unlock_restore instead to get rid of
> this error message.
>
> [ INFO: inconsistent lock state ]
> 3.13.0-rc1+ #287 Not tainted
> ---------------------------------
> inconsistent {IN-HARDIRQ-W} -> {HARDIRQ-ON-W} usage.
> kworker/u2:1/33 [HC0[0]:SC0[0]:HE1:SE1] takes:
>  (&(&host->lock)->rlock){?.-...}, at: [<8045f7f4>] sdhci_execute_tuning+0x4c/0x710
> {IN-HARDIRQ-W} state was registered at:
>   [<8005f030>] mark_lock+0x140/0x6ac
>   [<80060760>] __lock_acquire+0xb30/0x1cbc
>   [<800620d0>] lock_acquire+0x70/0x84
>   [<8061d1c8>] _raw_spin_lock+0x30/0x40
>   [<804605cc>] sdhci_irq+0x24/0xa68
>   [<8006b1d4>] handle_irq_event_percpu+0x54/0x18c
>   [<8006b350>] handle_irq_event+0x44/0x64
>   [<8006e50c>] handle_fasteoi_irq+0xa0/0x170
>   [<8006a8f0>] generic_handle_irq+0x30/0x44
>   [<8000f238>] handle_IRQ+0x54/0xbc
>   [<8000864c>] gic_handle_irq+0x30/0x64
>   [<80013024>] __irq_svc+0x44/0x5c
>   [<80329bf4>] dev_vprintk_emit+0x50/0x58
>   [<80329c24>] dev_printk_emit+0x28/0x30
>   [<80329fec>] __dev_printk+0x4c/0x90
>   [<8032a180>] dev_err+0x3c/0x48
>   [<802dd4f0>] _regulator_get+0x158/0x1cc
>   [<802dd5b4>] regulator_get_optional+0x18/0x1c
>   [<80461df4>] sdhci_add_host+0x42c/0xbd8
>   [<80464820>] sdhci_esdhc_imx_probe+0x378/0x67c
>   [<8032ee88>] platform_drv_probe+0x20/0x50
>   [<8032d48c>] driver_probe_device+0x118/0x234
>   [<8032d690>] __driver_attach+0x9c/0xa0
>   [<8032b89c>] bus_for_each_dev+0x68/0x9c
>   [<8032cf44>] driver_attach+0x20/0x28
>   [<8032cbc8>] bus_add_driver+0x148/0x1f4
>   [<8032dce0>] driver_register+0x80/0x100
>   [<8032ee54>] __platform_driver_register+0x50/0x64
>   [<8084b094>] sdhci_esdhc_imx_driver_init+0x18/0x20
>   [<80008980>] do_one_initcall+0x108/0x16c
>   [<8081cca4>] kernel_init_freeable+0x10c/0x1d0
>   [<80611b28>] kernel_init+0x10/0x120
>   [<8000e9c8>] ret_from_fork+0x14/0x2c
> irq event stamp: 805
> hardirqs last  enabled at (805): [<8061d43c>] _raw_spin_unlock_irqrestore+0x38/0x4c
> hardirqs last disabled at (804): [<8061d2c8>] _raw_spin_lock_irqsave+0x24/0x54
> softirqs last  enabled at (570): [<8002b824>] __do_softirq+0x1c4/0x290
> softirqs last disabled at (561): [<8002bcf4>] irq_exit+0xb4/0x10c
>
> other info that might help us debug this:
>  Possible unsafe locking scenario:
>
>        CPU0
>        ----
>   lock(&(&host->lock)->rlock);
>   <Interrupt>
>     lock(&(&host->lock)->rlock);
>
>  *** DEADLOCK ***
>
> 2 locks held by kworker/u2:1/33:
>  #0:  (kmmcd){.+.+..}, at: [<8003db18>] process_one_work+0x128/0x468
>  #1:  ((&(&host->detect)->work)){+.+...}, at: [<8003db18>] process_one_work+0x128/0x468
>
> stack backtrace:
> CPU: 0 PID: 33 Comm: kworker/u2:1 Not tainted 3.13.0-rc1+ #287
> Workqueue: kmmcd mmc_rescan
> Backtrace:
> [<80012160>] (dump_backtrace+0x0/0x10c) from [<80012438>] (show_stack+0x18/0x1c)
>  r6:bfad0900 r5:00000000 r4:8088ecc8 r3:bfad0900
> [<80012420>] (show_stack+0x0/0x1c) from [<806169ec>] (dump_stack+0x84/0x9c)
> [<80616968>] (dump_stack+0x0/0x9c) from [<806147b4>] (print_usage_bug+0x260/0x2d0)
>  r5:8076ba88 r4:80977410
> [<80614554>] (print_usage_bug+0x0/0x2d0) from [<8005f0d0>] (mark_lock+0x1e0/0x6ac)
>  r9:8005e678 r8:00000000 r7:bfad0900 r6:00001015 r5:bfad0cd0
> r4:00000002
> [<8005eef0>] (mark_lock+0x0/0x6ac) from [<80060234>] (__lock_acquire+0x604/0x1cbc)
> [<8005fc30>] (__lock_acquire+0x0/0x1cbc) from [<800620d0>] (lock_acquire+0x70/0x84)
> [<80062060>] (lock_acquire+0x0/0x84) from [<8061d1c8>] (_raw_spin_lock+0x30/0x40)
>  r7:00000000 r6:bfb63000 r5:00000000 r4:bfb60568
> [<8061d198>] (_raw_spin_lock+0x0/0x40) from [<8045f7f4>] (sdhci_execute_tuning+0x4c/0x710)
>  r4:bfb60000
> [<8045f7a8>] (sdhci_execute_tuning+0x0/0x710) from [<80453454>] (mmc_sd_init_card+0x5f8/0x660)
> [<80452e5c>] (mmc_sd_init_card+0x0/0x660) from [<80453748>] (mmc_attach_sd+0xb4/0x180)
>  r9:bf92d400 r8:8065f364 r7:00061a80 r6:bfb60000 r5:8065f358
> r4:bfb60000
> [<80453694>] (mmc_attach_sd+0x0/0x180) from [<8044d9f8>] (mmc_rescan+0x284/0x2f0)
>  r5:8065f358 r4:bfb602f8
> [<8044d774>] (mmc_rescan+0x0/0x2f0) from [<8003db94>] (process_one_work+0x1a4/0x468)
>  r8:00000000 r7:bfb55eb0 r6:bf80dc00 r5:bfb602f8 r4:bfb35980
> r3:8044d774
> [<8003d9f0>] (process_one_work+0x0/0x468) from [<8003e850>] (worker_thread+0x118/0x3e0)
> [<8003e738>] (worker_thread+0x0/0x3e0) from [<80044de0>] (kthread+0xd4/0xf0)
> [<80044d0c>] (kthread+0x0/0xf0) from [<8000e9c8>] (ret_from_fork+0x14/0x2c)
>  r7:00000000 r6:00000000 r5:80044d0c r4:bfb37b40
>
> Cc: Peter Zijlstra <peterz@infradead.org>
> Cc: Chris Ball <cjb@laptop.org>
> Cc: Shawn Guo <shawn.guo@linaro.org>
> Signed-off-by: Dong Aisheng <b29396@freescale.com>
>
> ---
> It's strange that this issue did not happen on kernel 3.10.17 with the same
> code. And looking at the code, before call spin_lock we already disable the mmc
> controller irq, per on my understanding, the deadlock given by lockdep may not
> be able to happen(pls fix me if wrong).
> May the lockdep not track the specific irq disable?
> Copy lockdep guy to comment.

Any comments for it?

Regards
Dong Aisheng

> ---
>  drivers/mmc/host/sdhci.c |   20 +++++++-------------
>  1 files changed, 7 insertions(+), 13 deletions(-)
>
> diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
> index a104bb1..c5d5f53 100644
> --- a/drivers/mmc/host/sdhci.c
> +++ b/drivers/mmc/host/sdhci.c
> @@ -1876,12 +1876,12 @@ static int sdhci_execute_tuning(struct mmc_host *mmc, u32 opcode)
>         unsigned long timeout;
>         int err = 0;
>         bool requires_tuning_nonuhs = false;
> +       unsigned long flags;
>
>         host = mmc_priv(mmc);
>
>         sdhci_runtime_pm_get(host);
> -       disable_irq(host->irq);
> -       spin_lock(&host->lock);
> +       spin_lock_irqsave(&host->lock, flags);
>
>         ctrl = sdhci_readw(host, SDHCI_HOST_CONTROL2);
>
> @@ -1901,15 +1901,13 @@ static int sdhci_execute_tuning(struct mmc_host *mmc, u32 opcode)
>             requires_tuning_nonuhs)
>                 ctrl |= SDHCI_CTRL_EXEC_TUNING;
>         else {
> -               spin_unlock(&host->lock);
> -               enable_irq(host->irq);
> +               spin_unlock_irqrestore(&host->lock, flags);
>                 sdhci_runtime_pm_put(host);
>                 return 0;
>         }
>
>         if (host->ops->platform_execute_tuning) {
> -               spin_unlock(&host->lock);
> -               enable_irq(host->irq);
> +               spin_unlock_irqrestore(&host->lock, flags);
>                 err = host->ops->platform_execute_tuning(host, opcode);
>                 sdhci_runtime_pm_put(host);
>                 return err;
> @@ -1982,15 +1980,12 @@ static int sdhci_execute_tuning(struct mmc_host *mmc, u32 opcode)
>                 host->cmd = NULL;
>                 host->mrq = NULL;
>
> -               spin_unlock(&host->lock);
> -               enable_irq(host->irq);
> -
> +               spin_unlock_irqrestore(&host->lock, flags);
>                 /* Wait for Buffer Read Ready interrupt */
>                 wait_event_interruptible_timeout(host->buf_ready_int,
>                                         (host->tuning_done == 1),
>                                         msecs_to_jiffies(50));
> -               disable_irq(host->irq);
> -               spin_lock(&host->lock);
> +               spin_lock_irqsave(&host->lock, flags);
>
>                 if (!host->tuning_done) {
>                         pr_info(DRIVER_NAME ": Timeout waiting for "
> @@ -2065,8 +2060,7 @@ out:
>                 err = 0;
>
>         sdhci_clear_set_irqs(host, SDHCI_INT_DATA_AVAIL, ier);
> -       spin_unlock(&host->lock);
> -       enable_irq(host->irq);
> +       spin_unlock_irqrestore(&host->lock, flags);
>         sdhci_runtime_pm_put(host);
>
>         return err;
> --
> 1.7.2.rc3
>
>
>
> _______________________________________________
> linux-arm-kernel mailing list
> linux-arm-kernel at lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

Re: [PATCH 1/1] mmc: sdhci: fix lockdep error on tunning routine

[Dong Aisheng]

Ping....

On Thu, Dec 26, 2013 at 3:58 PM, Dong Aisheng <dongas86@gmail.com> wrote:
> Hi Peter,
>
> On Mon, Dec 23, 2013 at 7:13 PM, Dong Aisheng <b29396@freescale.com> wrote:
>> The sdhci_execute_tuning routine gets lock separately by
>> disable_irq(host->irq);
>> spin_lock(&host->lock);
>> It will cause the following lockdep error message since the &host->lock
>> could also be got in irq context.
>> Use spin_lock_irqsave/spin_unlock_restore instead to get rid of
>> this error message.
>>
>> [ INFO: inconsistent lock state ]
>> 3.13.0-rc1+ #287 Not tainted
>> ---------------------------------
>> inconsistent {IN-HARDIRQ-W} -> {HARDIRQ-ON-W} usage.
>> kworker/u2:1/33 [HC0[0]:SC0[0]:HE1:SE1] takes:
>>  (&(&host->lock)->rlock){?.-...}, at: [<8045f7f4>] sdhci_execute_tuning+0x4c/0x710
>> {IN-HARDIRQ-W} state was registered at:
>>   [<8005f030>] mark_lock+0x140/0x6ac
>>   [<80060760>] __lock_acquire+0xb30/0x1cbc
>>   [<800620d0>] lock_acquire+0x70/0x84
>>   [<8061d1c8>] _raw_spin_lock+0x30/0x40
>>   [<804605cc>] sdhci_irq+0x24/0xa68
>>   [<8006b1d4>] handle_irq_event_percpu+0x54/0x18c
>>   [<8006b350>] handle_irq_event+0x44/0x64
>>   [<8006e50c>] handle_fasteoi_irq+0xa0/0x170
>>   [<8006a8f0>] generic_handle_irq+0x30/0x44
>>   [<8000f238>] handle_IRQ+0x54/0xbc
>>   [<8000864c>] gic_handle_irq+0x30/0x64
>>   [<80013024>] __irq_svc+0x44/0x5c
>>   [<80329bf4>] dev_vprintk_emit+0x50/0x58
>>   [<80329c24>] dev_printk_emit+0x28/0x30
>>   [<80329fec>] __dev_printk+0x4c/0x90
>>   [<8032a180>] dev_err+0x3c/0x48
>>   [<802dd4f0>] _regulator_get+0x158/0x1cc
>>   [<802dd5b4>] regulator_get_optional+0x18/0x1c
>>   [<80461df4>] sdhci_add_host+0x42c/0xbd8
>>   [<80464820>] sdhci_esdhc_imx_probe+0x378/0x67c
>>   [<8032ee88>] platform_drv_probe+0x20/0x50
>>   [<8032d48c>] driver_probe_device+0x118/0x234
>>   [<8032d690>] __driver_attach+0x9c/0xa0
>>   [<8032b89c>] bus_for_each_dev+0x68/0x9c
>>   [<8032cf44>] driver_attach+0x20/0x28
>>   [<8032cbc8>] bus_add_driver+0x148/0x1f4
>>   [<8032dce0>] driver_register+0x80/0x100
>>   [<8032ee54>] __platform_driver_register+0x50/0x64
>>   [<8084b094>] sdhci_esdhc_imx_driver_init+0x18/0x20
>>   [<80008980>] do_one_initcall+0x108/0x16c
>>   [<8081cca4>] kernel_init_freeable+0x10c/0x1d0
>>   [<80611b28>] kernel_init+0x10/0x120
>>   [<8000e9c8>] ret_from_fork+0x14/0x2c
>> irq event stamp: 805
>> hardirqs last  enabled at (805): [<8061d43c>] _raw_spin_unlock_irqrestore+0x38/0x4c
>> hardirqs last disabled at (804): [<8061d2c8>] _raw_spin_lock_irqsave+0x24/0x54
>> softirqs last  enabled at (570): [<8002b824>] __do_softirq+0x1c4/0x290
>> softirqs last disabled at (561): [<8002bcf4>] irq_exit+0xb4/0x10c
>>
>> other info that might help us debug this:
>>  Possible unsafe locking scenario:
>>
>>        CPU0
>>        ----
>>   lock(&(&host->lock)->rlock);
>>   <Interrupt>
>>     lock(&(&host->lock)->rlock);
>>
>>  *** DEADLOCK ***
>>
>> 2 locks held by kworker/u2:1/33:
>>  #0:  (kmmcd){.+.+..}, at: [<8003db18>] process_one_work+0x128/0x468
>>  #1:  ((&(&host->detect)->work)){+.+...}, at: [<8003db18>] process_one_work+0x128/0x468
>>
>> stack backtrace:
>> CPU: 0 PID: 33 Comm: kworker/u2:1 Not tainted 3.13.0-rc1+ #287
>> Workqueue: kmmcd mmc_rescan
>> Backtrace:
>> [<80012160>] (dump_backtrace+0x0/0x10c) from [<80012438>] (show_stack+0x18/0x1c)
>>  r6:bfad0900 r5:00000000 r4:8088ecc8 r3:bfad0900
>> [<80012420>] (show_stack+0x0/0x1c) from [<806169ec>] (dump_stack+0x84/0x9c)
>> [<80616968>] (dump_stack+0x0/0x9c) from [<806147b4>] (print_usage_bug+0x260/0x2d0)
>>  r5:8076ba88 r4:80977410
>> [<80614554>] (print_usage_bug+0x0/0x2d0) from [<8005f0d0>] (mark_lock+0x1e0/0x6ac)
>>  r9:8005e678 r8:00000000 r7:bfad0900 r6:00001015 r5:bfad0cd0
>> r4:00000002
>> [<8005eef0>] (mark_lock+0x0/0x6ac) from [<80060234>] (__lock_acquire+0x604/0x1cbc)
>> [<8005fc30>] (__lock_acquire+0x0/0x1cbc) from [<800620d0>] (lock_acquire+0x70/0x84)
>> [<80062060>] (lock_acquire+0x0/0x84) from [<8061d1c8>] (_raw_spin_lock+0x30/0x40)
>>  r7:00000000 r6:bfb63000 r5:00000000 r4:bfb60568
>> [<8061d198>] (_raw_spin_lock+0x0/0x40) from [<8045f7f4>] (sdhci_execute_tuning+0x4c/0x710)
>>  r4:bfb60000
>> [<8045f7a8>] (sdhci_execute_tuning+0x0/0x710) from [<80453454>] (mmc_sd_init_card+0x5f8/0x660)
>> [<80452e5c>] (mmc_sd_init_card+0x0/0x660) from [<80453748>] (mmc_attach_sd+0xb4/0x180)
>>  r9:bf92d400 r8:8065f364 r7:00061a80 r6:bfb60000 r5:8065f358
>> r4:bfb60000
>> [<80453694>] (mmc_attach_sd+0x0/0x180) from [<8044d9f8>] (mmc_rescan+0x284/0x2f0)
>>  r5:8065f358 r4:bfb602f8
>> [<8044d774>] (mmc_rescan+0x0/0x2f0) from [<8003db94>] (process_one_work+0x1a4/0x468)
>>  r8:00000000 r7:bfb55eb0 r6:bf80dc00 r5:bfb602f8 r4:bfb35980
>> r3:8044d774
>> [<8003d9f0>] (process_one_work+0x0/0x468) from [<8003e850>] (worker_thread+0x118/0x3e0)
>> [<8003e738>] (worker_thread+0x0/0x3e0) from [<80044de0>] (kthread+0xd4/0xf0)
>> [<80044d0c>] (kthread+0x0/0xf0) from [<8000e9c8>] (ret_from_fork+0x14/0x2c)
>>  r7:00000000 r6:00000000 r5:80044d0c r4:bfb37b40
>>
>> Cc: Peter Zijlstra <peterz@infradead.org>
>> Cc: Chris Ball <cjb@laptop.org>
>> Cc: Shawn Guo <shawn.guo@linaro.org>
>> Signed-off-by: Dong Aisheng <b29396@freescale.com>
>>
>> ---
>> It's strange that this issue did not happen on kernel 3.10.17 with the same
>> code. And looking at the code, before call spin_lock we already disable the mmc
>> controller irq, per on my understanding, the deadlock given by lockdep may not
>> be able to happen(pls fix me if wrong).
>> May the lockdep not track the specific irq disable?
>> Copy lockdep guy to comment.
>
> Any comments for it?
>
> Regards
> Dong Aisheng
>
>> ---
>>  drivers/mmc/host/sdhci.c |   20 +++++++-------------
>>  1 files changed, 7 insertions(+), 13 deletions(-)
>>
>> diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
>> index a104bb1..c5d5f53 100644
>> --- a/drivers/mmc/host/sdhci.c
>> +++ b/drivers/mmc/host/sdhci.c
>> @@ -1876,12 +1876,12 @@ static int sdhci_execute_tuning(struct mmc_host *mmc, u32 opcode)
>>         unsigned long timeout;
>>         int err = 0;
>>         bool requires_tuning_nonuhs = false;
>> +       unsigned long flags;
>>
>>         host = mmc_priv(mmc);
>>
>>         sdhci_runtime_pm_get(host);
>> -       disable_irq(host->irq);
>> -       spin_lock(&host->lock);
>> +       spin_lock_irqsave(&host->lock, flags);
>>
>>         ctrl = sdhci_readw(host, SDHCI_HOST_CONTROL2);
>>
>> @@ -1901,15 +1901,13 @@ static int sdhci_execute_tuning(struct mmc_host *mmc, u32 opcode)
>>             requires_tuning_nonuhs)
>>                 ctrl |= SDHCI_CTRL_EXEC_TUNING;
>>         else {
>> -               spin_unlock(&host->lock);
>> -               enable_irq(host->irq);
>> +               spin_unlock_irqrestore(&host->lock, flags);
>>                 sdhci_runtime_pm_put(host);
>>                 return 0;
>>         }
>>
>>         if (host->ops->platform_execute_tuning) {
>> -               spin_unlock(&host->lock);
>> -               enable_irq(host->irq);
>> +               spin_unlock_irqrestore(&host->lock, flags);
>>                 err = host->ops->platform_execute_tuning(host, opcode);
>>                 sdhci_runtime_pm_put(host);
>>                 return err;
>> @@ -1982,15 +1980,12 @@ static int sdhci_execute_tuning(struct mmc_host *mmc, u32 opcode)
>>                 host->cmd = NULL;
>>                 host->mrq = NULL;
>>
>> -               spin_unlock(&host->lock);
>> -               enable_irq(host->irq);
>> -
>> +               spin_unlock_irqrestore(&host->lock, flags);
>>                 /* Wait for Buffer Read Ready interrupt */
>>                 wait_event_interruptible_timeout(host->buf_ready_int,
>>                                         (host->tuning_done == 1),
>>                                         msecs_to_jiffies(50));
>> -               disable_irq(host->irq);
>> -               spin_lock(&host->lock);
>> +               spin_lock_irqsave(&host->lock, flags);
>>
>>                 if (!host->tuning_done) {
>>                         pr_info(DRIVER_NAME ": Timeout waiting for "
>> @@ -2065,8 +2060,7 @@ out:
>>                 err = 0;
>>
>>         sdhci_clear_set_irqs(host, SDHCI_INT_DATA_AVAIL, ier);
>> -       spin_unlock(&host->lock);
>> -       enable_irq(host->irq);
>> +       spin_unlock_irqrestore(&host->lock, flags);
>>         sdhci_runtime_pm_put(host);
>>
>>         return err;
>> --
>> 1.7.2.rc3
>>
>>
>>
>> _______________________________________________
>> linux-arm-kernel mailing list
>> linux-arm-kernel@lists.infradead.org
>> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

[PATCH 1/1] mmc: sdhci: fix lockdep error on tunning routine

[Dong Aisheng]

Ping....

On Thu, Dec 26, 2013 at 3:58 PM, Dong Aisheng <dongas86@gmail.com> wrote:
> Hi Peter,
>
> On Mon, Dec 23, 2013 at 7:13 PM, Dong Aisheng <b29396@freescale.com> wrote:
>> The sdhci_execute_tuning routine gets lock separately by
>> disable_irq(host->irq);
>> spin_lock(&host->lock);
>> It will cause the following lockdep error message since the &host->lock
>> could also be got in irq context.
>> Use spin_lock_irqsave/spin_unlock_restore instead to get rid of
>> this error message.
>>
>> [ INFO: inconsistent lock state ]
>> 3.13.0-rc1+ #287 Not tainted
>> ---------------------------------
>> inconsistent {IN-HARDIRQ-W} -> {HARDIRQ-ON-W} usage.
>> kworker/u2:1/33 [HC0[0]:SC0[0]:HE1:SE1] takes:
>>  (&(&host->lock)->rlock){?.-...}, at: [<8045f7f4>] sdhci_execute_tuning+0x4c/0x710
>> {IN-HARDIRQ-W} state was registered at:
>>   [<8005f030>] mark_lock+0x140/0x6ac
>>   [<80060760>] __lock_acquire+0xb30/0x1cbc
>>   [<800620d0>] lock_acquire+0x70/0x84
>>   [<8061d1c8>] _raw_spin_lock+0x30/0x40
>>   [<804605cc>] sdhci_irq+0x24/0xa68
>>   [<8006b1d4>] handle_irq_event_percpu+0x54/0x18c
>>   [<8006b350>] handle_irq_event+0x44/0x64
>>   [<8006e50c>] handle_fasteoi_irq+0xa0/0x170
>>   [<8006a8f0>] generic_handle_irq+0x30/0x44
>>   [<8000f238>] handle_IRQ+0x54/0xbc
>>   [<8000864c>] gic_handle_irq+0x30/0x64
>>   [<80013024>] __irq_svc+0x44/0x5c
>>   [<80329bf4>] dev_vprintk_emit+0x50/0x58
>>   [<80329c24>] dev_printk_emit+0x28/0x30
>>   [<80329fec>] __dev_printk+0x4c/0x90
>>   [<8032a180>] dev_err+0x3c/0x48
>>   [<802dd4f0>] _regulator_get+0x158/0x1cc
>>   [<802dd5b4>] regulator_get_optional+0x18/0x1c
>>   [<80461df4>] sdhci_add_host+0x42c/0xbd8
>>   [<80464820>] sdhci_esdhc_imx_probe+0x378/0x67c
>>   [<8032ee88>] platform_drv_probe+0x20/0x50
>>   [<8032d48c>] driver_probe_device+0x118/0x234
>>   [<8032d690>] __driver_attach+0x9c/0xa0
>>   [<8032b89c>] bus_for_each_dev+0x68/0x9c
>>   [<8032cf44>] driver_attach+0x20/0x28
>>   [<8032cbc8>] bus_add_driver+0x148/0x1f4
>>   [<8032dce0>] driver_register+0x80/0x100
>>   [<8032ee54>] __platform_driver_register+0x50/0x64
>>   [<8084b094>] sdhci_esdhc_imx_driver_init+0x18/0x20
>>   [<80008980>] do_one_initcall+0x108/0x16c
>>   [<8081cca4>] kernel_init_freeable+0x10c/0x1d0
>>   [<80611b28>] kernel_init+0x10/0x120
>>   [<8000e9c8>] ret_from_fork+0x14/0x2c
>> irq event stamp: 805
>> hardirqs last  enabled at (805): [<8061d43c>] _raw_spin_unlock_irqrestore+0x38/0x4c
>> hardirqs last disabled at (804): [<8061d2c8>] _raw_spin_lock_irqsave+0x24/0x54
>> softirqs last  enabled at (570): [<8002b824>] __do_softirq+0x1c4/0x290
>> softirqs last disabled at (561): [<8002bcf4>] irq_exit+0xb4/0x10c
>>
>> other info that might help us debug this:
>>  Possible unsafe locking scenario:
>>
>>        CPU0
>>        ----
>>   lock(&(&host->lock)->rlock);
>>   <Interrupt>
>>     lock(&(&host->lock)->rlock);
>>
>>  *** DEADLOCK ***
>>
>> 2 locks held by kworker/u2:1/33:
>>  #0:  (kmmcd){.+.+..}, at: [<8003db18>] process_one_work+0x128/0x468
>>  #1:  ((&(&host->detect)->work)){+.+...}, at: [<8003db18>] process_one_work+0x128/0x468
>>
>> stack backtrace:
>> CPU: 0 PID: 33 Comm: kworker/u2:1 Not tainted 3.13.0-rc1+ #287
>> Workqueue: kmmcd mmc_rescan
>> Backtrace:
>> [<80012160>] (dump_backtrace+0x0/0x10c) from [<80012438>] (show_stack+0x18/0x1c)
>>  r6:bfad0900 r5:00000000 r4:8088ecc8 r3:bfad0900
>> [<80012420>] (show_stack+0x0/0x1c) from [<806169ec>] (dump_stack+0x84/0x9c)
>> [<80616968>] (dump_stack+0x0/0x9c) from [<806147b4>] (print_usage_bug+0x260/0x2d0)
>>  r5:8076ba88 r4:80977410
>> [<80614554>] (print_usage_bug+0x0/0x2d0) from [<8005f0d0>] (mark_lock+0x1e0/0x6ac)
>>  r9:8005e678 r8:00000000 r7:bfad0900 r6:00001015 r5:bfad0cd0
>> r4:00000002
>> [<8005eef0>] (mark_lock+0x0/0x6ac) from [<80060234>] (__lock_acquire+0x604/0x1cbc)
>> [<8005fc30>] (__lock_acquire+0x0/0x1cbc) from [<800620d0>] (lock_acquire+0x70/0x84)
>> [<80062060>] (lock_acquire+0x0/0x84) from [<8061d1c8>] (_raw_spin_lock+0x30/0x40)
>>  r7:00000000 r6:bfb63000 r5:00000000 r4:bfb60568
>> [<8061d198>] (_raw_spin_lock+0x0/0x40) from [<8045f7f4>] (sdhci_execute_tuning+0x4c/0x710)
>>  r4:bfb60000
>> [<8045f7a8>] (sdhci_execute_tuning+0x0/0x710) from [<80453454>] (mmc_sd_init_card+0x5f8/0x660)
>> [<80452e5c>] (mmc_sd_init_card+0x0/0x660) from [<80453748>] (mmc_attach_sd+0xb4/0x180)
>>  r9:bf92d400 r8:8065f364 r7:00061a80 r6:bfb60000 r5:8065f358
>> r4:bfb60000
>> [<80453694>] (mmc_attach_sd+0x0/0x180) from [<8044d9f8>] (mmc_rescan+0x284/0x2f0)
>>  r5:8065f358 r4:bfb602f8
>> [<8044d774>] (mmc_rescan+0x0/0x2f0) from [<8003db94>] (process_one_work+0x1a4/0x468)
>>  r8:00000000 r7:bfb55eb0 r6:bf80dc00 r5:bfb602f8 r4:bfb35980
>> r3:8044d774
>> [<8003d9f0>] (process_one_work+0x0/0x468) from [<8003e850>] (worker_thread+0x118/0x3e0)
>> [<8003e738>] (worker_thread+0x0/0x3e0) from [<80044de0>] (kthread+0xd4/0xf0)
>> [<80044d0c>] (kthread+0x0/0xf0) from [<8000e9c8>] (ret_from_fork+0x14/0x2c)
>>  r7:00000000 r6:00000000 r5:80044d0c r4:bfb37b40
>>
>> Cc: Peter Zijlstra <peterz@infradead.org>
>> Cc: Chris Ball <cjb@laptop.org>
>> Cc: Shawn Guo <shawn.guo@linaro.org>
>> Signed-off-by: Dong Aisheng <b29396@freescale.com>
>>
>> ---
>> It's strange that this issue did not happen on kernel 3.10.17 with the same
>> code. And looking at the code, before call spin_lock we already disable the mmc
>> controller irq, per on my understanding, the deadlock given by lockdep may not
>> be able to happen(pls fix me if wrong).
>> May the lockdep not track the specific irq disable?
>> Copy lockdep guy to comment.
>
> Any comments for it?
>
> Regards
> Dong Aisheng
>
>> ---
>>  drivers/mmc/host/sdhci.c |   20 +++++++-------------
>>  1 files changed, 7 insertions(+), 13 deletions(-)
>>
>> diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
>> index a104bb1..c5d5f53 100644
>> --- a/drivers/mmc/host/sdhci.c
>> +++ b/drivers/mmc/host/sdhci.c
>> @@ -1876,12 +1876,12 @@ static int sdhci_execute_tuning(struct mmc_host *mmc, u32 opcode)
>>         unsigned long timeout;
>>         int err = 0;
>>         bool requires_tuning_nonuhs = false;
>> +       unsigned long flags;
>>
>>         host = mmc_priv(mmc);
>>
>>         sdhci_runtime_pm_get(host);
>> -       disable_irq(host->irq);
>> -       spin_lock(&host->lock);
>> +       spin_lock_irqsave(&host->lock, flags);
>>
>>         ctrl = sdhci_readw(host, SDHCI_HOST_CONTROL2);
>>
>> @@ -1901,15 +1901,13 @@ static int sdhci_execute_tuning(struct mmc_host *mmc, u32 opcode)
>>             requires_tuning_nonuhs)
>>                 ctrl |= SDHCI_CTRL_EXEC_TUNING;
>>         else {
>> -               spin_unlock(&host->lock);
>> -               enable_irq(host->irq);
>> +               spin_unlock_irqrestore(&host->lock, flags);
>>                 sdhci_runtime_pm_put(host);
>>                 return 0;
>>         }
>>
>>         if (host->ops->platform_execute_tuning) {
>> -               spin_unlock(&host->lock);
>> -               enable_irq(host->irq);
>> +               spin_unlock_irqrestore(&host->lock, flags);
>>                 err = host->ops->platform_execute_tuning(host, opcode);
>>                 sdhci_runtime_pm_put(host);
>>                 return err;
>> @@ -1982,15 +1980,12 @@ static int sdhci_execute_tuning(struct mmc_host *mmc, u32 opcode)
>>                 host->cmd = NULL;
>>                 host->mrq = NULL;
>>
>> -               spin_unlock(&host->lock);
>> -               enable_irq(host->irq);
>> -
>> +               spin_unlock_irqrestore(&host->lock, flags);
>>                 /* Wait for Buffer Read Ready interrupt */
>>                 wait_event_interruptible_timeout(host->buf_ready_int,
>>                                         (host->tuning_done == 1),
>>                                         msecs_to_jiffies(50));
>> -               disable_irq(host->irq);
>> -               spin_lock(&host->lock);
>> +               spin_lock_irqsave(&host->lock, flags);
>>
>>                 if (!host->tuning_done) {
>>                         pr_info(DRIVER_NAME ": Timeout waiting for "
>> @@ -2065,8 +2060,7 @@ out:
>>                 err = 0;
>>
>>         sdhci_clear_set_irqs(host, SDHCI_INT_DATA_AVAIL, ier);
>> -       spin_unlock(&host->lock);
>> -       enable_irq(host->irq);
>> +       spin_unlock_irqrestore(&host->lock, flags);
>>         sdhci_runtime_pm_put(host);
>>
>>         return err;
>> --
>> 1.7.2.rc3
>>
>>
>>
>> _______________________________________________
>> linux-arm-kernel mailing list
>> linux-arm-kernel at lists.infradead.org
>> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

Re: [PATCH 1/1] mmc: sdhci: fix lockdep error on tunning routine

[Peter Zijlstra]

On Thu, Dec 26, 2013 at 03:58:20PM +0800, Dong Aisheng wrote:
> > It's strange that this issue did not happen on kernel 3.10.17 with the same
> > code. And looking at the code, before call spin_lock we already disable the mmc
> > controller irq, per on my understanding, the deadlock given by lockdep may not
> > be able to happen(pls fix me if wrong).
> > May the lockdep not track the specific irq disable?
> > Copy lockdep guy to comment.

No, lockdep also doesn't know only that one line can take this lock.
Lockdep only knows a lock is taken from IRQ context, and disabling one
line still allows IRQs to happen and therefore it yells.

[PATCH 1/1] mmc: sdhci: fix lockdep error on tunning routine

[Peter Zijlstra]

On Thu, Dec 26, 2013 at 03:58:20PM +0800, Dong Aisheng wrote:
> > It's strange that this issue did not happen on kernel 3.10.17 with the same
> > code. And looking at the code, before call spin_lock we already disable the mmc
> > controller irq, per on my understanding, the deadlock given by lockdep may not
> > be able to happen(pls fix me if wrong).
> > May the lockdep not track the specific irq disable?
> > Copy lockdep guy to comment.

No, lockdep also doesn't know only that one line can take this lock.
Lockdep only knows a lock is taken from IRQ context, and disabling one
line still allows IRQs to happen and therefore it yells.

Re: [PATCH 1/1] mmc: sdhci: fix lockdep error on tunning routine

[Dong Aisheng]

On Mon, Jan 13, 2014 at 8:04 PM, Peter Zijlstra <peterz@infradead.org> wrote:
> On Thu, Dec 26, 2013 at 03:58:20PM +0800, Dong Aisheng wrote:
>> > It's strange that this issue did not happen on kernel 3.10.17 with the same
>> > code. And looking at the code, before call spin_lock we already disable the mmc
>> > controller irq, per on my understanding, the deadlock given by lockdep may not
>> > be able to happen(pls fix me if wrong).
>> > May the lockdep not track the specific irq disable?
>> > Copy lockdep guy to comment.
>
> No, lockdep also doesn't know only that one line can take this lock.
> Lockdep only knows a lock is taken from IRQ context, and disabling one
> line still allows IRQs to happen and therefore it yells.

Okay, thanks for the information.
If that, kernel 3.10.17 has the same code, do you know why it does not trigger
such lockdep error?

Regards
Dong Aisheng

[PATCH 1/1] mmc: sdhci: fix lockdep error on tunning routine

[Dong Aisheng]

On Mon, Jan 13, 2014 at 8:04 PM, Peter Zijlstra <peterz@infradead.org> wrote:
> On Thu, Dec 26, 2013 at 03:58:20PM +0800, Dong Aisheng wrote:
>> > It's strange that this issue did not happen on kernel 3.10.17 with the same
>> > code. And looking at the code, before call spin_lock we already disable the mmc
>> > controller irq, per on my understanding, the deadlock given by lockdep may not
>> > be able to happen(pls fix me if wrong).
>> > May the lockdep not track the specific irq disable?
>> > Copy lockdep guy to comment.
>
> No, lockdep also doesn't know only that one line can take this lock.
> Lockdep only knows a lock is taken from IRQ context, and disabling one
> line still allows IRQs to happen and therefore it yells.

Okay, thanks for the information.
If that, kernel 3.10.17 has the same code, do you know why it does not trigger
such lockdep error?

Regards
Dong Aisheng

Re: [PATCH 1/1] mmc: sdhci: fix lockdep error on tunning routine

[Lothar Waßmann]

Hi,

Dong Aisheng wrote:
> On Mon, Jan 13, 2014 at 8:04 PM, Peter Zijlstra <peterz@infradead.org> wrote:
> > On Thu, Dec 26, 2013 at 03:58:20PM +0800, Dong Aisheng wrote:
> >> > It's strange that this issue did not happen on kernel 3.10.17 with the same
> >> > code. And looking at the code, before call spin_lock we already disable the mmc
> >> > controller irq, per on my understanding, the deadlock given by lockdep may not
> >> > be able to happen(pls fix me if wrong).
> >> > May the lockdep not track the specific irq disable?
> >> > Copy lockdep guy to comment.
> >
> > No, lockdep also doesn't know only that one line can take this lock.
> > Lockdep only knows a lock is taken from IRQ context, and disabling one
> > line still allows IRQs to happen and therefore it yells.
> 
> Okay, thanks for the information.
> If that, kernel 3.10.17 has the same code, do you know why it does not trigger
> such lockdep error?
> 
compiled with CONFIG_LOCKDEP disabled?


Lothar Waßmann
-- 
___________________________________________________________

Ka-Ro electronics GmbH | Pascalstraße 22 | D - 52076 Aachen
Phone: +49 2408 1402-0 | Fax: +49 2408 1402-10
Geschäftsführer: Matthias Kaussen
Handelsregistereintrag: Amtsgericht Aachen, HRB 4996

www.karo-electronics.de | info@karo-electronics.de
___________________________________________________________

[PATCH 1/1] mmc: sdhci: fix lockdep error on tunning routine

[Lothar Waßmann]

Hi,

Dong Aisheng wrote:
> On Mon, Jan 13, 2014 at 8:04 PM, Peter Zijlstra <peterz@infradead.org> wrote:
> > On Thu, Dec 26, 2013 at 03:58:20PM +0800, Dong Aisheng wrote:
> >> > It's strange that this issue did not happen on kernel 3.10.17 with the same
> >> > code. And looking at the code, before call spin_lock we already disable the mmc
> >> > controller irq, per on my understanding, the deadlock given by lockdep may not
> >> > be able to happen(pls fix me if wrong).
> >> > May the lockdep not track the specific irq disable?
> >> > Copy lockdep guy to comment.
> >
> > No, lockdep also doesn't know only that one line can take this lock.
> > Lockdep only knows a lock is taken from IRQ context, and disabling one
> > line still allows IRQs to happen and therefore it yells.
> 
> Okay, thanks for the information.
> If that, kernel 3.10.17 has the same code, do you know why it does not trigger
> such lockdep error?
> 
compiled with CONFIG_LOCKDEP disabled?


Lothar Wa?mann
-- 
___________________________________________________________

Ka-Ro electronics GmbH | Pascalstra?e 22 | D - 52076 Aachen
Phone: +49 2408 1402-0 | Fax: +49 2408 1402-10
Gesch?ftsf?hrer: Matthias Kaussen
Handelsregistereintrag: Amtsgericht Aachen, HRB 4996

www.karo-electronics.de | info at karo-electronics.de
___________________________________________________________

Re: [PATCH 1/1] mmc: sdhci: fix lockdep error on tunning routine

[Dong Aisheng]

On Wed, Jan 15, 2014 at 3:46 PM, Lothar Waßmann <LW@karo-electronics.de> wrote:
> Hi,
>
> Dong Aisheng wrote:
>> On Mon, Jan 13, 2014 at 8:04 PM, Peter Zijlstra <peterz@infradead.org> wrote:
>> > On Thu, Dec 26, 2013 at 03:58:20PM +0800, Dong Aisheng wrote:
>> >> > It's strange that this issue did not happen on kernel 3.10.17 with the same
>> >> > code. And looking at the code, before call spin_lock we already disable the mmc
>> >> > controller irq, per on my understanding, the deadlock given by lockdep may not
>> >> > be able to happen(pls fix me if wrong).
>> >> > May the lockdep not track the specific irq disable?
>> >> > Copy lockdep guy to comment.
>> >
>> > No, lockdep also doesn't know only that one line can take this lock.
>> > Lockdep only knows a lock is taken from IRQ context, and disabling one
>> > line still allows IRQs to happen and therefore it yells.
>>
>> Okay, thanks for the information.
>> If that, kernel 3.10.17 has the same code, do you know why it does not trigger
>> such lockdep error?
>>
> compiled with CONFIG_LOCKDEP disabled?
>

I did compile with LOCKDEP enabled.
See below for a part of my .config
CONFIG_DEBUG_SPINLOCK=y
CONFIG_DEBUG_MUTEXES=y
CONFIG_DEBUG_LOCK_ALLOC=y
CONFIG_PROVE_LOCKING=y
CONFIG_LOCKDEP=y
# CONFIG_LOCK_STAT is not set
# CONFIG_DEBUG_LOCKDEP is not set
CONFIG_TRACE_IRQFLAGS=y
CONFIG_DEBUG_ATOMIC_SLEEP=y

That's why i think it's strange.

Regards
Dong Aisheng

>
> Lothar Waßmann
> --
> ___________________________________________________________
>
> Ka-Ro electronics GmbH | Pascalstraße 22 | D - 52076 Aachen
> Phone: +49 2408 1402-0 | Fax: +49 2408 1402-10
> Geschäftsführer: Matthias Kaussen
> Handelsregistereintrag: Amtsgericht Aachen, HRB 4996
>
> www.karo-electronics.de | info@karo-electronics.de
> ___________________________________________________________

[PATCH 1/1] mmc: sdhci: fix lockdep error on tunning routine

[Dong Aisheng]

On Wed, Jan 15, 2014 at 3:46 PM, Lothar Wa?mann <LW@karo-electronics.de> wrote:
> Hi,
>
> Dong Aisheng wrote:
>> On Mon, Jan 13, 2014 at 8:04 PM, Peter Zijlstra <peterz@infradead.org> wrote:
>> > On Thu, Dec 26, 2013 at 03:58:20PM +0800, Dong Aisheng wrote:
>> >> > It's strange that this issue did not happen on kernel 3.10.17 with the same
>> >> > code. And looking at the code, before call spin_lock we already disable the mmc
>> >> > controller irq, per on my understanding, the deadlock given by lockdep may not
>> >> > be able to happen(pls fix me if wrong).
>> >> > May the lockdep not track the specific irq disable?
>> >> > Copy lockdep guy to comment.
>> >
>> > No, lockdep also doesn't know only that one line can take this lock.
>> > Lockdep only knows a lock is taken from IRQ context, and disabling one
>> > line still allows IRQs to happen and therefore it yells.
>>
>> Okay, thanks for the information.
>> If that, kernel 3.10.17 has the same code, do you know why it does not trigger
>> such lockdep error?
>>
> compiled with CONFIG_LOCKDEP disabled?
>

I did compile with LOCKDEP enabled.
See below for a part of my .config
CONFIG_DEBUG_SPINLOCK=y
CONFIG_DEBUG_MUTEXES=y
CONFIG_DEBUG_LOCK_ALLOC=y
CONFIG_PROVE_LOCKING=y
CONFIG_LOCKDEP=y
# CONFIG_LOCK_STAT is not set
# CONFIG_DEBUG_LOCKDEP is not set
CONFIG_TRACE_IRQFLAGS=y
CONFIG_DEBUG_ATOMIC_SLEEP=y

That's why i think it's strange.

Regards
Dong Aisheng

>
> Lothar Wa?mann
> --
> ___________________________________________________________
>
> Ka-Ro electronics GmbH | Pascalstra?e 22 | D - 52076 Aachen
> Phone: +49 2408 1402-0 | Fax: +49 2408 1402-10
> Gesch?ftsf?hrer: Matthias Kaussen
> Handelsregistereintrag: Amtsgericht Aachen, HRB 4996
>
> www.karo-electronics.de | info at karo-electronics.de
> ___________________________________________________________

Re: [PATCH 1/1] mmc: sdhci: fix lockdep error on tunning routine

[Peter Zijlstra]

On Wed, Jan 15, 2014 at 03:19:27PM +0800, Dong Aisheng wrote:
> On Mon, Jan 13, 2014 at 8:04 PM, Peter Zijlstra <peterz@infradead.org> wrote:
> > On Thu, Dec 26, 2013 at 03:58:20PM +0800, Dong Aisheng wrote:
> >> > It's strange that this issue did not happen on kernel 3.10.17 with the same
> >> > code. And looking at the code, before call spin_lock we already disable the mmc
> >> > controller irq, per on my understanding, the deadlock given by lockdep may not
> >> > be able to happen(pls fix me if wrong).
> >> > May the lockdep not track the specific irq disable?
> >> > Copy lockdep guy to comment.
> >
> > No, lockdep also doesn't know only that one line can take this lock.
> > Lockdep only knows a lock is taken from IRQ context, and disabling one
> > line still allows IRQs to happen and therefore it yells.
> 
> Okay, thanks for the information.
> If that, kernel 3.10.17 has the same code, do you know why it does not trigger
> such lockdep error?

No idea; there haven't really been big lockdep changes recently.

[PATCH 1/1] mmc: sdhci: fix lockdep error on tunning routine

[Peter Zijlstra]

On Wed, Jan 15, 2014 at 03:19:27PM +0800, Dong Aisheng wrote:
> On Mon, Jan 13, 2014 at 8:04 PM, Peter Zijlstra <peterz@infradead.org> wrote:
> > On Thu, Dec 26, 2013 at 03:58:20PM +0800, Dong Aisheng wrote:
> >> > It's strange that this issue did not happen on kernel 3.10.17 with the same
> >> > code. And looking at the code, before call spin_lock we already disable the mmc
> >> > controller irq, per on my understanding, the deadlock given by lockdep may not
> >> > be able to happen(pls fix me if wrong).
> >> > May the lockdep not track the specific irq disable?
> >> > Copy lockdep guy to comment.
> >
> > No, lockdep also doesn't know only that one line can take this lock.
> > Lockdep only knows a lock is taken from IRQ context, and disabling one
> > line still allows IRQs to happen and therefore it yells.
> 
> Okay, thanks for the information.
> If that, kernel 3.10.17 has the same code, do you know why it does not trigger
> such lockdep error?

No idea; there haven't really been big lockdep changes recently.

Re: [PATCH 1/1] mmc: sdhci: fix lockdep error on tunning routine

[Dong Aisheng]

On Wed, Jan 15, 2014 at 6:09 PM, Peter Zijlstra <peterz@infradead.org> wrote:
> On Wed, Jan 15, 2014 at 03:19:27PM +0800, Dong Aisheng wrote:
>> On Mon, Jan 13, 2014 at 8:04 PM, Peter Zijlstra <peterz@infradead.org> wrote:
>> > On Thu, Dec 26, 2013 at 03:58:20PM +0800, Dong Aisheng wrote:
>> >> > It's strange that this issue did not happen on kernel 3.10.17 with the same
>> >> > code. And looking at the code, before call spin_lock we already disable the mmc
>> >> > controller irq, per on my understanding, the deadlock given by lockdep may not
>> >> > be able to happen(pls fix me if wrong).
>> >> > May the lockdep not track the specific irq disable?
>> >> > Copy lockdep guy to comment.
>> >
>> > No, lockdep also doesn't know only that one line can take this lock.
>> > Lockdep only knows a lock is taken from IRQ context, and disabling one
>> > line still allows IRQs to happen and therefore it yells.
>>
>> Okay, thanks for the information.
>> If that, kernel 3.10.17 has the same code, do you know why it does not trigger
>> such lockdep error?
>
> No idea; there haven't really been big lockdep changes recently.

Okay, thanks.
Anyway, this patch fix should be needed to avoid the lockdep error.

Chirs,
Can you pick it up?

Regards
Dong Aisheng

[PATCH 1/1] mmc: sdhci: fix lockdep error on tunning routine

[Dong Aisheng]

On Wed, Jan 15, 2014 at 6:09 PM, Peter Zijlstra <peterz@infradead.org> wrote:
> On Wed, Jan 15, 2014 at 03:19:27PM +0800, Dong Aisheng wrote:
>> On Mon, Jan 13, 2014 at 8:04 PM, Peter Zijlstra <peterz@infradead.org> wrote:
>> > On Thu, Dec 26, 2013 at 03:58:20PM +0800, Dong Aisheng wrote:
>> >> > It's strange that this issue did not happen on kernel 3.10.17 with the same
>> >> > code. And looking at the code, before call spin_lock we already disable the mmc
>> >> > controller irq, per on my understanding, the deadlock given by lockdep may not
>> >> > be able to happen(pls fix me if wrong).
>> >> > May the lockdep not track the specific irq disable?
>> >> > Copy lockdep guy to comment.
>> >
>> > No, lockdep also doesn't know only that one line can take this lock.
>> > Lockdep only knows a lock is taken from IRQ context, and disabling one
>> > line still allows IRQs to happen and therefore it yells.
>>
>> Okay, thanks for the information.
>> If that, kernel 3.10.17 has the same code, do you know why it does not trigger
>> such lockdep error?
>
> No idea; there haven't really been big lockdep changes recently.

Okay, thanks.
Anyway, this patch fix should be needed to avoid the lockdep error.

Chirs,
Can you pick it up?

Regards
Dong Aisheng