[RESEND PATCH] ARM: fix 'unannotated irqs-on' lockdep warning

[RESEND PATCH] ARM: fix 'unannotated irqs-on' lockdep warning

[tom.leiming]

From: Ming Lei <tom.leiming@gmail.com>

This patch fixes the 'unannotated irqs-on' lockdep warning[1]:

This patch introduces macro of trace_ret_hardirqs_on, which will
call trace_hardirqs_on if I flag in the stored CPSR is zero.

In the path of returning to user-space, the patch replaces disable_irq
with disable_irq_notrace in ret_to_user to avoid the 'unannotated irqs-on'
lockdep warning since hardirqs is always enabled before returning to user.

In the path of returning to kernel-space, the patch still replaces
disable_irq with disable_irq_notrace in __xxx_svc handler and adds
trace_hardirqs_on before calling svc_exit to trace the possible hardirqs on
event for avoiding the possible 'unannotated irqs-on' lockdep warning.

The patch not only fixes the warning[1] to make lockdep usable on ARM,
but also improves the efficiency if lockdep is enabled:

	- remove one calling for asm_trace_hardirqs_on before returning
to user-space
	- convert asm_trace_hardirqs_on to trace_hardirqs_on in the
path of returning to kernel space from exception and __only__ call it if
harirqs will be enabled before returning.

[1]
	CPU: Testing write buffer coherency: ok
	------------[ cut here ]------------
	WARNING: at kernel/lockdep.c:3145 check_flags+0xcc/0x1dc()
	Modules linked in:
	[<c0035120>] (unwind_backtrace+0x0/0xf8) from [<c0355374>] (dump_stack+0x20/0x24)
	[<c0355374>] (dump_stack+0x20/0x24) from [<c0060c04>] (warn_slowpath_common+0x58/0x70)
	[<c0060c04>] (warn_slowpath_common+0x58/0x70) from [<c0060c3c>] (warn_slowpath_null+0x20/0x24)
	[<c0060c3c>] (warn_slowpath_null+0x20/0x24) from [<c008f224>] (check_flags+0xcc/0x1dc)
	[<c008f224>] (check_flags+0xcc/0x1dc) from [<c00945dc>] (lock_acquire+0x50/0x140)
	[<c00945dc>] (lock_acquire+0x50/0x140) from [<c0358434>] (_raw_spin_lock+0x50/0x88)
	[<c0358434>] (_raw_spin_lock+0x50/0x88) from [<c00fd114>] (set_task_comm+0x2c/0x60)
	[<c00fd114>] (set_task_comm+0x2c/0x60) from [<c007e184>] (kthreadd+0x30/0x108)
	[<c007e184>] (kthreadd+0x30/0x108) from [<c0030104>] (kernel_thread_exit+0x0/0x8)
	---[ end trace 1b75b31a2719ed1c ]---
	possible reason: unannotated irqs-on.
	irq event stamp: 3
	hardirqs last  enabled at (2): [<c0059bb0>] finish_task_switch+0x48/0xb0
	hardirqs last disabled at (3): [<c002f0b0>] ret_slow_syscall+0xc/0x1c
	softirqs last  enabled at (0): [<c005f3e0>] copy_process+0x394/0xe5c
	softirqs last disabled at (0): [<(null)>] (null)

Signed-off-by: Ming Lei <tom.leiming@gmail.com>
---
 arch/arm/kernel/entry-armv.S   |   31 +++++++++++++++++--------------
 arch/arm/kernel/entry-common.S |    2 +-
 arch/arm/kernel/entry-header.S |    7 +++++++
 3 files changed, 25 insertions(+), 15 deletions(-)

diff --git a/arch/arm/kernel/entry-armv.S b/arch/arm/kernel/entry-armv.S
index 7ee48e7..42d33cf 100644
--- a/arch/arm/kernel/entry-armv.S
+++ b/arch/arm/kernel/entry-armv.S
@@ -204,13 +204,15 @@ __dabt_svc:
 	@
 	@ IRQs off again before pulling preserved data off the stack
 	@
-	disable_irq
+	disable_irq_notrace
 
 	@
 	@ restore SPSR and restart the instruction
+	@ trace possible hardirqs on event before returning
 	@
-	ldr	r2, [sp, #S_PSR]
-	svc_exit r2				@ return from exception
+	ldr	r4, [sp, #S_PSR]
+	trace_ret_hardirqs_on r4
+	svc_exit r4				@ return from exception
  UNWIND(.fnend		)
 ENDPROC(__dabt_svc)
 
@@ -235,10 +237,7 @@ __irq_svc:
 	blne	svc_preempt
 #endif
 	ldr	r4, [sp, #S_PSR]		@ irqs are already disabled
-#ifdef CONFIG_TRACE_IRQFLAGS
-	tst	r4, #PSR_I_BIT
-	bleq	trace_hardirqs_on
-#endif
+	trace_ret_hardirqs_on r4
 	svc_exit r4				@ return from exception
  UNWIND(.fnend		)
 ENDPROC(__irq_svc)
@@ -291,13 +290,15 @@ __und_svc:
 	@
 	@ IRQs off again before pulling preserved data off the stack
 	@
-1:	disable_irq
+1:	disable_irq_notrace
 
 	@
 	@ restore SPSR and restart the instruction
+	@ trace possible hardirqs on event before returning
 	@
-	ldr	r2, [sp, #S_PSR]		@ Get SVC cpsr
-	svc_exit r2				@ return from exception
+	ldr	r4, [sp, #S_PSR]		@ Get SVC cpsr
+	trace_ret_hardirqs_on r4
+	svc_exit r4				@ return from exception
  UNWIND(.fnend		)
 ENDPROC(__und_svc)
 
@@ -327,13 +328,15 @@ __pabt_svc:
 	@
 	@ IRQs off again before pulling preserved data off the stack
 	@
-	disable_irq
+	disable_irq_notrace
 
 	@
 	@ restore SPSR and restart the instruction
-	@
-	ldr	r2, [sp, #S_PSR]
-	svc_exit r2				@ return from exception
+	@ trace possible hardirqs on event before returning
+	@	
+	ldr	r4, [sp, #S_PSR]
+	trace_ret_hardirqs_on r4
+	svc_exit r4				@ return from exception
  UNWIND(.fnend		)
 ENDPROC(__pabt_svc)
 
diff --git a/arch/arm/kernel/entry-common.S b/arch/arm/kernel/entry-common.S
index 2c1db77..ed471a7 100644
--- a/arch/arm/kernel/entry-common.S
+++ b/arch/arm/kernel/entry-common.S
@@ -58,7 +58,7 @@ work_resched:
  */
 ENTRY(ret_to_user)
 ret_slow_syscall:
-	disable_irq				@ disable interrupts
+	disable_irq_notrace				@ disable interrupts
 	ldr	r1, [tsk, #TI_FLAGS]
 	tst	r1, #_TIF_WORK_MASK
 	bne	work_pending
diff --git a/arch/arm/kernel/entry-header.S b/arch/arm/kernel/entry-header.S
index d93f976..ac51ce3 100644
--- a/arch/arm/kernel/entry-header.S
+++ b/arch/arm/kernel/entry-header.S
@@ -30,6 +30,13 @@
 #error "Please fix"
 #endif
 
+	.macro trace_ret_hardirqs_on, rspsr
+#ifdef CONFIG_TRACE_IRQFLAGS
+	tst 	\rspsr, #PSR_I_BIT
+	bleq	trace_hardirqs_on
+#endif
+	.endm
+
 	.macro	zero_fp
 #ifdef CONFIG_FRAME_POINTER
 	mov	fp, #0
-- 
1.6.2.5

Re: [RESEND PATCH] ARM: fix 'unannotated irqs-on' lockdep warning

[Russell King - ARM Linux]

On Sun, May 23, 2010 at 07:48:48PM +0800, tom.leiming@gmail.com wrote:
> diff --git a/arch/arm/kernel/entry-common.S b/arch/arm/kernel/entry-common.S
> index 2c1db77..ed471a7 100644
> --- a/arch/arm/kernel/entry-common.S
> +++ b/arch/arm/kernel/entry-common.S
> @@ -58,7 +58,7 @@ work_resched:
>   */
>  ENTRY(ret_to_user)
>  ret_slow_syscall:
> -	disable_irq				@ disable interrupts
> +	disable_irq_notrace				@ disable interrupts

I think this one does need to be traced - the pending work functions are
all C code which could call back into lockdep.

Also, I'm nervious about applying this patch without seeing more people
test it.

Re: [RESEND PATCH] ARM: fix 'unannotated irqs-on' lockdep warning

[Ming Lei]

2010/5/23 Russell King - ARM Linux <linux@arm.linux.org.uk>:
>>  ENTRY(ret_to_user)
>>  ret_slow_syscall:
>> -     disable_irq                             @ disable interrupts
>> +     disable_irq_notrace                             @ disable interrupts
>
> I think this one does need to be traced - the pending work functions are
> all C code which could call back into lockdep.

If there are pending works, schedule will be called to give cpu to it, I wonder
why the work function to be scheduled will be run with irq disabled.
Seems we should enable irq again before calling schedule, not sure.

> Also, I'm nervious about applying this patch without seeing more people
> test it.

I test the patch on my beagle board and is OK, and if you don't apply one
patch into your tree, there are few people who may test it since they have to
parse the raw email patch(which is more inconvenient than 'git pull') for test
if they want to do.

Thanks,
-- 
Lei Ming

Re: [RESEND PATCH] ARM: fix 'unannotated irqs-on' lockdep warning

[Russell King - ARM Linux]

On Sun, May 23, 2010 at 09:44:20PM +0800, Ming Lei wrote:
> 2010/5/23 Russell King - ARM Linux <linux@arm.linux.org.uk>:
> >>  ENTRY(ret_to_user)
> >>  ret_slow_syscall:
> >> -     disable_irq                             @ disable interrupts
> >> +     disable_irq_notrace                             @ disable interrupts
> >
> > I think this one does need to be traced - the pending work functions are
> > all C code which could call back into lockdep.
> 
> If there are pending works, schedule will be called to give cpu to it,
> I wonder why the work function to be scheduled will be run with irq
> disabled. Seems we should enable irq again before calling schedule,
> not sure.

No.  I'm talking about things like do_notify_resume().

I think the above should be left as-is, so that as far as lockdep is
concerned, IRQs are off while userspace runs.  What happens between
returning to userspace and re-entering the kernel has no bearing what
so ever on lockdep.

Re: [RESEND PATCH] ARM: fix 'unannotated irqs-on' lockdep warning

[Ming Lei]

2010/5/23 Russell King - ARM Linux <linux@arm.linux.org.uk>:
> On Sun, May 23, 2010 at 09:44:20PM +0800, Ming Lei wrote:
>> 2010/5/23 Russell King - ARM Linux <linux@arm.linux.org.uk>:
>> >>  ENTRY(ret_to_user)
>> >>  ret_slow_syscall:
>> >> -     disable_irq                             @ disable interrupts
>> >> +     disable_irq_notrace                             @ disable interrupts
>> >
>> > I think this one does need to be traced - the pending work functions are
>> > all C code which could call back into lockdep.
>>
>> If there are pending works, schedule will be called to give cpu to it,
>> I wonder why the work function to be scheduled will be run with irq
>> disabled. Seems we should enable irq again before calling schedule,
>> not sure.
>
> No.  I'm talking about things like do_notify_resume().
>
> I think the above should be left as-is, so that as far as lockdep is
> concerned, IRQs are off while userspace runs.  What happens between
> returning to userspace and re-entering the kernel has no bearing what
> so ever on lockdep.
>

Oh, trace_ret_hardirqs_on has to be added before returning to user-space to
remove the warning, like x86 and mips. If you agree, I'd like to post
a new version
patch.

Thanks,

-- 
Lei Ming

Re: [RESEND PATCH] ARM: fix 'unannotated irqs-on' lockdep warning

[Russell King - ARM Linux]

On Sun, May 23, 2010 at 11:07:50PM +0800, Ming Lei wrote:
> 2010/5/23 Russell King - ARM Linux <linux@arm.linux.org.uk>:
> > On Sun, May 23, 2010 at 09:44:20PM +0800, Ming Lei wrote:
> >> 2010/5/23 Russell King - ARM Linux <linux@arm.linux.org.uk>:
> >> >>  ENTRY(ret_to_user)
> >> >>  ret_slow_syscall:
> >> >> -     disable_irq                             @ disable interrupts
> >> >> +     disable_irq_notrace                             @ disable interrupts
> >> >
> >> > I think this one does need to be traced - the pending work functions are
> >> > all C code which could call back into lockdep.
> >>
> >> If there are pending works, schedule will be called to give cpu to it,
> >> I wonder why the work function to be scheduled will be run with irq
> >> disabled. Seems we should enable irq again before calling schedule,
> >> not sure.
> >
> > No.  I'm talking about things like do_notify_resume().
> >
> > I think the above should be left as-is, so that as far as lockdep is
> > concerned, IRQs are off while userspace runs.  What happens between
> > returning to userspace and re-entering the kernel has no bearing what
> > so ever on lockdep.
> >
> 
> Oh, trace_ret_hardirqs_on has to be added before returning to user-space to
> remove the warning, like x86 and mips. If you agree, I'd like to post
> a new version patch.

Let me explain again.  We have this series of actions:

- in userspace
- exception happens
- cpu disables interrupts itself
- save state
- enable interrupts, and tell lockdep that IRQs are unmasked
- we process the exception, and ultimately call ret_fast_syscall or
  ret_slow_syscall

Now, what was happening in existing kernels is:

POINT A.
- disable interrupts, and tell lockdep that IRQs are masked
- check for any work pending
  - if work pending, call function - with IRQs still masked
  - go back to point A.
- restore state
- resume userspace, which implicitly re-enables IRQs

This results in a balanced and afaics correct setup.  Lockdep doesn't
care about the state of userspace - it only cares about state (and its
code only ever runs) when we're in kernel mode.

With your change above, what's happening is the above is replaced by:

POINT A.
- disable interrupts, but don't tell lockdep that IRQs are masked
- check for any work pending
  - if work pending, call function - with IRQs still masked
	*but* lockdep believes IRQs are enabled.  Therefore, I believe
	false warnings are probable from things like the scheduler,
	signal handling paths, etc.
  - go back to point A.
- restore state
- resume userspace, which implicitly re-enables IRQs

So can you now see why I believe the above change I've quoted is wrong?

Moreover, I put to you that it's utterly pointless - and a waste of CPU
time - telling lockdep about the IRQ masking when an exception occurs,
and it's also pointless telling lockdep about the IRQ unmasking when we
resume userspace.

Re: [RESEND PATCH] ARM: fix 'unannotated irqs-on' lockdep warning

[Ming Lei]

On Sun, 23 May 2010 20:47:46 +0100
Russell King - ARM Linux <linux@arm.linux.org.uk> wrote:

> Let me explain again.  We have this series of actions:
> 
> - in userspace
> - exception happens
> - cpu disables interrupts itself
> - save state
> - enable interrupts, and tell lockdep that IRQs are unmasked
> - we process the exception, and ultimately call ret_fast_syscall or
>   ret_slow_syscall
> 
> Now, what was happening in existing kernels is:
> 
> POINT A.
> - disable interrupts, and tell lockdep that IRQs are masked
> - check for any work pending
>   - if work pending, call function - with IRQs still masked
>   - go back to point A.
> - restore state
> - resume userspace, which implicitly re-enables IRQs
> 
> This results in a balanced and afaics correct setup.  Lockdep doesn't
> care about the state of userspace - it only cares about state (and its
> code only ever runs) when we're in kernel mode.
> 
> With your change above, what's happening is the above is replaced by:
> 
> POINT A.
> - disable interrupts, but don't tell lockdep that IRQs are masked
> - check for any work pending
>   - if work pending, call function - with IRQs still masked
> 	*but* lockdep believes IRQs are enabled.  Therefore, I believe
> 	false warnings are probable from things like the scheduler,
> 	signal handling paths, etc.
>   - go back to point A.
> - restore state
> - resume userspace, which implicitly re-enables IRQs
> 
> So can you now see why I believe the above change I've quoted is
> wrong?

Yes, you are right, so we can fix it by the two ways below:

	-keep disable_irq in ret_slow_syscall, also add a extra 
	trace_ret_hardirqs_on before resume userspace.
or 
	-replace disable_irq with disable_irq_notrace in ret_slow_syscall
	and ret_fast_syscall, also add a extra trace_ret_hardirqs_off if
	there are works pending

seems the 2nd way is more efficient.

> 
> Moreover, I put to you that it's utterly pointless - and a waste of
> CPU time - telling lockdep about the IRQ masking when an exception

Yes, the patch still tries to remove the pointless trace of IRQ masking,
such as: replace disable_irq with disable_irq_notrace.

> occurs, and it's also pointless telling lockdep about the IRQ
> unmasking when we resume userspace.

Even it is pointless, but if lockdep doesn't see the IRQ unmasking, the 
warning "unannotated irqs-on" will be triggered and lockdep doe not work
any longer, so we have to remove the warning to make lockdep workable on
ARM, could you agree on it?  It is the main purpose of the patch.

The warning was reported before and still exists in 2.6.34 and -next tree:

        http://marc.info/?l=linux-arm-kernel&m=126047420005553&w=2


Thanks,
Ming Lei

Re: [RESEND PATCH] ARM: fix 'unannotated irqs-on' lockdep warning

[Russell King - ARM Linux]

On Mon, May 24, 2010 at 11:23:55AM +0800, Ming Lei wrote:
> On Sun, 23 May 2010 20:47:46 +0100
> Russell King - ARM Linux <linux@arm.linux.org.uk> wrote:
> > Moreover, I put to you that it's utterly pointless - and a waste of
> > CPU time - telling lockdep about the IRQ masking when an exception
> 
> Yes, the patch still tries to remove the pointless trace of IRQ masking,
> such as: replace disable_irq with disable_irq_notrace.
> 
> > occurs, and it's also pointless telling lockdep about the IRQ
> > unmasking when we resume userspace.
> 
> Even it is pointless, but if lockdep doesn't see the IRQ unmasking, the 
> warning "unannotated irqs-on" will be triggered and lockdep doe not work
> any longer, so we have to remove the warning to make lockdep workable on
> ARM, could you agree on it?  It is the main purpose of the patch.

I'm sorry, I think we have a communication issue; you're not understanding
the points that I'm making.  I feel I'm wasting my time trying to explain
it.

I'm not merging your patch as-is because I believe it to be wrong.

Re: [RESEND PATCH] ARM: fix 'unannotated irqs-on' lockdep warning

[Russell King - ARM Linux]

On Mon, May 24, 2010 at 08:19:21AM +0100, Russell King - ARM Linux wrote:
> On Mon, May 24, 2010 at 11:23:55AM +0800, Ming Lei wrote:
> > On Sun, 23 May 2010 20:47:46 +0100
> > Russell King - ARM Linux <linux@arm.linux.org.uk> wrote:
> > > Moreover, I put to you that it's utterly pointless - and a waste of
> > > CPU time - telling lockdep about the IRQ masking when an exception
> > 
> > Yes, the patch still tries to remove the pointless trace of IRQ masking,
> > such as: replace disable_irq with disable_irq_notrace.
> > 
> > > occurs, and it's also pointless telling lockdep about the IRQ
> > > unmasking when we resume userspace.
> > 
> > Even it is pointless, but if lockdep doesn't see the IRQ unmasking, the 
> > warning "unannotated irqs-on" will be triggered and lockdep doe not work
> > any longer, so we have to remove the warning to make lockdep workable on
> > ARM, could you agree on it?  It is the main purpose of the patch.
> 
> I'm sorry, I think we have a communication issue; you're not understanding
> the points that I'm making.  I feel I'm wasting my time trying to explain
> it.
> 
> I'm not merging your patch as-is because I believe it to be wrong.

Right, I see what the problem is now - it's all to do with threads
created with kernel_thread() confusing lockdep.

I'm of the opinion that all your changes in entry*.S are the wrong
way to fix this - not only does it add additional overhead where
none is really necessary, it adds additional complexity.

So, here's a patch to solve the warning you quoted.

diff --git a/arch/arm/kernel/process.c b/arch/arm/kernel/process.c
index acf5e6f..a5f8fd0 100644
--- a/arch/arm/kernel/process.c
+++ b/arch/arm/kernel/process.c
@@ -351,17 +351,25 @@ EXPORT_SYMBOL(dump_fpu);
 
 /*
  * Shuffle the argument into the correct register before calling the
- * thread function.  r1 is the thread argument, r2 is the pointer to
- * the thread function, and r3 points to the exit function.
+ * thread function.  r4 is the thread argument, r5 is the pointer to
+ * the thread function, and r6 points to the exit function.
  */
 extern void kernel_thread_helper(void);
 asm(	".pushsection .text\n"
 "	.align\n"
 "	.type	kernel_thread_helper, #function\n"
 "kernel_thread_helper:\n"
-"	mov	r0, r1\n"
-"	mov	lr, r3\n"
-"	mov	pc, r2\n"
+#ifdef CONFIG_TRACE_IRQFLAGS
+"	bl	trace_hardirqs_on\n"
+#endif
+#if __LINUX_ARM_ARCH__ >= 6
+"	cpsie	i\n"
+#else
+"	msr	cpsr_c, r7\n"
+#endif
+"	mov	r0, r4\n"
+"	mov	lr, r6\n"
+"	mov	pc, r5\n"
 "	.size	kernel_thread_helper, . - kernel_thread_helper\n"
 "	.popsection");
 
@@ -391,11 +399,12 @@ pid_t kernel_thread(int (*fn)(void *), void *arg, unsigned long flags)
 
 	memset(&regs, 0, sizeof(regs));
 
-	regs.ARM_r1 = (unsigned long)arg;
-	regs.ARM_r2 = (unsigned long)fn;
-	regs.ARM_r3 = (unsigned long)kernel_thread_exit;
+	regs.ARM_r4 = (unsigned long)arg;
+	regs.ARM_r5 = (unsigned long)fn;
+	regs.ARM_r6 = (unsigned long)kernel_thread_exit;
+	regs.ARM_r7 = SVC_MODE | PSR_ISETSTATE;
 	regs.ARM_pc = (unsigned long)kernel_thread_helper;
-	regs.ARM_cpsr = SVC_MODE | PSR_ENDSTATE | PSR_ISETSTATE;
+	regs.ARM_cpsr = SVC_MODE | PSR_ENDSTATE | PSR_ISETSTATE | PSR_I_BIT;
 
 	return do_fork(flags|CLONE_VM|CLONE_UNTRACED, 0, &regs, 0, NULL, NULL);
 }

Re: [RESEND PATCH] ARM: fix 'unannotated irqs-on' lockdep warning

[Ming Lei]

On Mon, 24 May 2010 11:14:16 +0100
Russell King - ARM Linux <linux@arm.linux.org.uk> wrote:

> Right, I see what the problem is now - it's all to do with threads
> created with kernel_thread() confusing lockdep.
> 
> I'm of the opinion that all your changes in entry*.S are the wrong
> way to fix this - not only does it add additional overhead where
> none is really necessary, it adds additional complexity.
> 
> So, here's a patch to solve the warning you quoted.

No, your patch does not fix the issue, I still can see the lockdep
warning after applying it against Linux 2.6.34-next-20100524.

Follows the dmesg info:

Texas Instruments X-Loader 1.4.4ss (Apr 13 2010 - 22:36:28)
Beagle Rev C4
Reading boot sector
Loading u-boot.bin from mmc


U-Boot 2010.03 (May 04 2010 - 08:48:31)

OMAP3530-GP ES3.1, CPU-OPP2, L3-165MHz, Max clock-720Mhz
OMAP3 Beagle board + LPDDR/NAND
I2C:   ready
DRAM:  256 MB
NAND:  256 MiB
In:    serial
Out:   serial
Err:   serial

Probing for expansion boards, if none are connected you'll see a harmless I2C error.

timed out in wait_for_pin: I2C_STAT=0
I2C read: I/O error
Unrecognized expansion board: 0
Beagle Rev C4
Die ID #16c00004000000000403730515017007
Hit any key to stop autoboot:  3 \b\b\b 2 \b\b\b 1 \b\b\b 0 
OMAP3 beagleboard.org # prit\b \bntenv
baudrate=115200
loadaddr=0x80200000
rdaddr=0x81600000
console=ttyS2,115200n8
optargs=
mmcargs=setenv bootargs console=${console} ${optargs} root=/dev/mmcblk0p2 rw rootfstype=ext3 rootwait
ramargs=setenv bootargs console=${console} ${optargs} root=/dev/ram0 rw ramdisk_size=32768 initrd=${rdaddr},32M
ubifsargs=setenv bootargs console=${console} ${optargs} root=ubi0:beagleroot ubi.mtd=4 rw rootfstype=ubifs
jffs2args=setenv bootargs console=${console} ${optargs} root=/dev/mtdblock4 rw rootfstype=jffs2
loadbootscript=fatload mmc 0 ${loadaddr} boot.scr
bootscript=echo Running bootscript from mmc ...; autoscr ${loadaddr}
loadramdisk=fatload mmc 0 ${rdaddr} ramdisk.gz
ramboot=echo Booting from ramdisk.gz ...; run ramargs; bootm ${loadaddr}
mmcboot=echo Booting from mmc ...; run mmcargs; bootm ${loadaddr}
nandboot=echo Booting from nand ...; run jffs2args; nand read ${loadaddr} 280000 400000; bootm ${loadaddr}
usbtty=cdc_acm
stdout=serial,usbtty
stdin=serial,usbtty
stderr=serial,usbtty
serial=16c00004000000000403730515017007
dieid#=16c00004000000000403730515017007
restore_c41=mmc init;fatload mmc 0 82000000 MLO;nand unlock;nandecc hw;nand erase 0 80000;nand write 82000000 0 20000;nand write 82000000 20000 20000;nand write 82000000 40000 20000;nand write 82000000 60000 20000
restore_c42=fatload mmc 0 0x80200000 u-boot.bin;nand unlock;nandecc sw;nand erase 80000 160000;nand write 0x80200000 80000 160000
mtdids=nand0=nand
bootcmd=mmc init;run loaduimage;run mmcboot
restore_fac=if mmc init; then if run loadbootscript; then run bootscript; else if run loaduimage; then if run loadramdisk;then run ramboot; else run mmcboot; fi; else run nandboot; fi; fi; else run nandboot; fi
loaduimage=fatload mmc 0 ${loadaddr} uImage
bootdelay=3
buddy=unknown
mpurate=720

Environment size: 1771/131068 bytes
OMAP3 beagleboard.org # setenv loaduimage 'fatload mmc 0 ${loadaddr} uImage-next'
OMAP3 beagleboard.org # run bootcmd
mmc1 is available
reading uImage-next

2707936 bytes read
Booting from mmc ...
## Booting kernel from Legacy Image at 80200000 ...
   Image Name:   Linux-2.6.34-next-20100524+
   Image Type:   ARM Linux Kernel Image (uncompressed)
   Data Size:    2707872 Bytes =  2.6 MB
   Load Address: 80008000
   Entry Point:  80008000
   Verifying Checksum ... OK
   Loading Kernel Image ... OK
OK

Starting kernel ...

Uncompressing Linux... done, booting the kernel.
[    0.000000] Linux version 2.6.34-next-20100524+ (tom@tom-lei) (gcc version 4.3.3 (Sourcery G++ Lite 2009q1-203) ) #56 PREEMPT Mon May 24 21:56:03 CST 2010
[    0.000000] CPU: ARMv7 Processor [411fc083] revision 3 (ARMv7), cr=10c53c7f
[    0.000000] CPU: VIPT nonaliasing data cache, VIPT nonaliasing instruction cache
[    0.000000] Machine: OMAP3 Beagle Board
[    0.000000] Memory policy: ECC disabled, Data cache writeback
[    0.000000] OMAP3430/3530 ES3.1 (l2cache iva sgx neon isp )
[    0.000000] SRAM: Mapped pa 0x40200000 to va 0xfe400000 size: 0x100000
[    0.000000] Built 1 zonelists in Zone order, mobility grouping on.  Total pages: 65024
[    0.000000] Kernel command line: console=ttyS2,115200n8 root=/dev/mmcblk0p2 rw rootfstype=ext3 rootwait
[    0.000000] PID hash table entries: 1024 (order: 0, 4096 bytes)
[    0.000000] Dentry cache hash table entries: 32768 (order: 5, 131072 bytes)
[    0.000000] Inode-cache hash table entries: 16384 (order: 4, 65536 bytes)
[    0.000000] Memory: 128MB 128MB = 256MB total
[    0.000000] Memory: 245020k/245020k available, 17124k reserved, 0K highmem
[    0.000000] Virtual kernel memory layout:
[    0.000000]     vector  : 0xffff0000 - 0xffff1000   (   4 kB)
[    0.000000]     fixmap  : 0xfff00000 - 0xfffe0000   ( 896 kB)
[    0.000000]     DMA     : 0xffc00000 - 0xffe00000   (   2 MB)
[    0.000000]     vmalloc : 0xd0800000 - 0xf8000000   ( 632 MB)
[    0.000000]     lowmem  : 0xc0000000 - 0xd0000000   ( 256 MB)
[    0.000000]     modules : 0xbf000000 - 0xc0000000   (  16 MB)
[    0.000000]       .init : 0xc0008000 - 0xc0039000   ( 196 kB)
[    0.000000]       .text : 0xc0039000 - 0xc050d000   (4944 kB)
[    0.000000]       .data : 0xc0564000 - 0xc0717ab0   (1743 kB)
[    0.000000] Hierarchical RCU implementation.
[    0.000000] 	Verbose stalled-CPUs detection is disabled.
[    0.000000] NR_IRQS:402
[    0.000000] Clocking rate (Crystal/Core/MPU): 26.0/332/500 MHz
[    0.000000] omap_hwmod: l3_hwmod: cannot be enabled (3)
[    0.000000] omap_hwmod: l4_core_hwmod: cannot be enabled (3)
[    0.000000] omap_hwmod: l4_per_hwmod: cannot be enabled (3)
[    0.000000] omap_hwmod: l4_wkup_hwmod: cannot be enabled (3)
[    0.000000] Reprogramming SDRC clock to 332000000 Hz
[    0.000000] GPMC revision 5.0
[    0.000000] IRQ: Found an INTC at 0xfa200000 (revision 4.0) with 96 interrupts
[    0.000000] Total of 96 interrupts on 1 active controller
[    0.000000] OMAP GPIO hardware version 2.5
[    0.000000] OMAP clockevent source: GPTIMER12 at 32768 Hz
[    0.000000] Console: colour dummy device 80x30
[    0.000000] Lock dependency validator: Copyright (c) 2006 Red Hat, Inc., Ingo Molnar
[    0.000000] ... MAX_LOCKDEP_SUBCLASSES:  8
[    0.000000] ... MAX_LOCK_DEPTH:          48
[    0.000000] ... MAX_LOCKDEP_KEYS:        8191
[    0.000000] ... CLASSHASH_SIZE:          4096
[    0.000000] ... MAX_LOCKDEP_ENTRIES:     16384
[    0.000000] ... MAX_LOCKDEP_CHAINS:      32768
[    0.000000] ... CHAINHASH_SIZE:          16384
[    0.000000]  memory used by lock dependency info: 3951 kB
[    0.000000]  per task-struct memory footprint: 2304 bytes
[    0.000000] ------------------------
[    0.000000] | Locking API testsuite:
[    0.000000] ----------------------------------------------------------------------------
[    0.000000]                                  | spin |wlock |rlock |mutex | wsem | rsem |
[    0.000000]   --------------------------------------------------------------------------
[    0.000000]                      A-A deadlock:  ok  |  ok  |  ok  |  ok  |  ok  |  ok  |
[    0.000000]                  A-B-B-A deadlock:  ok  |  ok  |  ok  |  ok  |  ok  |  ok  |
[    0.000000]              A-B-B-C-C-A deadlock:  ok  |  ok  |  ok  |  ok  |  ok  |  ok  |
[    0.000000]              A-B-C-A-B-C deadlock:  ok  |  ok  |  ok  |  ok  |  ok  |  ok  |
[    0.000000]          A-B-B-C-C-D-D-A deadlock:  ok  |  ok  |  ok  |  ok  |  ok  |  ok  |
[    0.000000]          A-B-C-D-B-D-D-A deadlock:  ok  |  ok  |  ok  |  ok  |  ok  |  ok  |
[    0.000000]          A-B-C-D-B-C-D-A deadlock:  ok  |  ok  |  ok  |  ok  |  ok  |  ok  |
[    0.000000]                     double unlock:  ok  |  ok  |  ok  |  ok  |  ok  |  ok  |
[    0.000000]                   initialize held:  ok  |  ok  |  ok  |  ok  |  ok  |  ok  |
[    0.000000]                  bad unlock order:  ok  |  ok  |  ok  |  ok  |  ok  |  ok  |
[    0.000000]   --------------------------------------------------------------------------
[    0.000000]               recursive read-lock:             |  ok  |             |  ok  |
[    0.000000]            recursive read-lock #2:             |  ok  |             |  ok  |
[    0.000000]             mixed read-write-lock:             |  ok  |             |  ok  |
[    0.000000]             mixed write-read-lock:             |  ok  |             |  ok  |
[    0.000000]   --------------------------------------------------------------------------
[    0.000000]      hard-irqs-on + irq-safe-A/12:  ok  |  ok  |  ok  |
[    0.000000]      soft-irqs-on + irq-safe-A/12:  ok  |  ok  |  ok  |
[    0.000000]      hard-irqs-on + irq-safe-A/21:  ok  |  ok  |  ok  |
[    0.000000]      soft-irqs-on + irq-safe-A/21:  ok  |  ok  |  ok  |
[    0.000000]        sirq-safe-A => hirqs-on/12:  ok  |  ok  |  ok  |
[    0.000000]        sirq-safe-A => hirqs-on/21:  ok  |  ok  |  ok  |
[    0.000000]          hard-safe-A + irqs-on/12:  ok  |  ok  |  ok  |
[    0.000000]          soft-safe-A + irqs-on/12:  ok  |  ok  |  ok  |
[    0.000000]          hard-safe-A + irqs-on/21:  ok  |  ok  |  ok  |
[    0.000000]          soft-safe-A + irqs-on/21:  ok  |  ok  |  ok  |
[    0.000000]     hard-safe-A + unsafe-B #1/123:  ok  |  ok  |  ok  |
[    0.000000]     soft-safe-A + unsafe-B #1/123:  ok  |  ok  |  ok  |
[    0.000000]     hard-safe-A + unsafe-B #1/132:  ok  |  ok  |  ok  |
[    0.000000]     soft-safe-A + unsafe-B #1/132:  ok  |  ok  |  ok  |
[    0.000000]     hard-safe-A + unsafe-B #1/213:  ok  |  ok  |  ok  |
[    0.000000]     soft-safe-A + unsafe-B #1/213:  ok  |  ok  |  ok  |
[    0.000000]     hard-safe-A + unsafe-B #1/231:  ok  |  ok  |  ok  |
[    0.000000]     soft-safe-A + unsafe-B #1/231:  ok  |  ok  |  ok  |
[    0.000000]     hard-safe-A + unsafe-B #1/312:  ok  |  ok  |  ok  |
[    0.000000]     soft-safe-A + unsafe-B #1/312:  ok  |  ok  |  ok  |
[    0.000000]     hard-safe-A + unsafe-B #1/321:  ok  |  ok  |  ok  |
[    0.000000]     soft-safe-A + unsafe-B #1/321:  ok  |  ok  |  ok  |
[    0.000000]     hard-safe-A + unsafe-B #2/123:  ok  |  ok  |  ok  |
[    0.000000]     soft-safe-A + unsafe-B #2/123:  ok  |  ok  |  ok  |
[    0.000000]     hard-safe-A + unsafe-B #2/132:  ok  |  ok  |  ok  |
[    0.000000]     soft-safe-A + unsafe-B #2/132:  ok  |  ok  |  ok  |
[    0.000000]     hard-safe-A + unsafe-B #2/213:  ok  |  ok  |  ok  |
[    0.000000]     soft-safe-A + unsafe-B #2/213:  ok  |  ok  |  ok  |
[    0.000000]     hard-safe-A + unsafe-B #2/231:  ok  |  ok  |  ok  |
[    0.000000]     soft-safe-A + unsafe-B #2/231:  ok  |  ok  |  ok  |
[    0.000000]     hard-safe-A + unsafe-B #2/312:  ok  |  ok  |  ok  |
[    0.000000]     soft-safe-A + unsafe-B #2/312:  ok  |  ok  |  ok  |
[    0.000000]     hard-safe-A + unsafe-B #2/321:  ok  |  ok  |  ok  |
[    0.000000]     soft-safe-A + unsafe-B #2/321:  ok  |  ok  |  ok  |
[    0.000000]       hard-irq lock-inversion/123:  ok  |  ok  |  ok  |
[    0.000000]       soft-irq lock-inversion/123:  ok  |  ok  |  ok  |
[    0.000000]       hard-irq lock-inversion/132:  ok  |  ok  |  ok  |
[    0.000000]       soft-irq lock-inversion/132:  ok  |  ok  |  ok  |
[    0.000000]       hard-irq lock-inversion/213:  ok  |  ok  |  ok  |
[    0.000000]       soft-irq lock-inversion/213:  ok  |  ok  |  ok  |
[    0.000000]       hard-irq lock-inversion/231:  ok  |  ok  |  ok  |
[    0.000000]       soft-irq lock-inversion/231:  ok  |  ok  |  ok  |
[    0.000000]       hard-irq lock-inversion/312:  ok  |  ok  |  ok  |
[    0.000000]       soft-irq lock-inversion/312:  ok  |  ok  |  ok  |
[    0.000000]       hard-irq lock-inversion/321:  ok  |  ok  |  ok  |
[    0.000000]       soft-irq lock-inversion/321:  ok  |  ok  |  ok  |
[    0.000000]       hard-irq read-recursion/123:  ok  |
[    0.000000]       soft-irq read-recursion/123:  ok  |
[    0.000000]       hard-irq read-recursion/132:  ok  |
[    0.000000]       soft-irq read-recursion/132:  ok  |
[    0.000000]       hard-irq read-recursion/213:  ok  |
[    0.000000]       soft-irq read-recursion/213:  ok  |
[    0.000000]       hard-irq read-recursion/231:  ok  |
[    0.000000]       soft-irq read-recursion/231:  ok  |
[    0.000000]       hard-irq read-recursion/312:  ok  |
[    0.000000]       soft-irq read-recursion/312:  ok  |
[    0.000000]       hard-irq read-recursion/321:  ok  |
[    0.000000]       soft-irq read-recursion/321:  ok  |
[    0.000000] -------------------------------------------------------
[    0.000000] Good, all 218 testcases passed! |
[    0.000000] ---------------------------------
[    0.000000] Calibrating delay loop... 497.82 BogoMIPS (lpj=1941504)
[    0.000000] Mount-cache hash table entries: 512
[    0.000000] CPU: Testing write buffer coherency: ok
[    0.000000] devtmpfs: initialized
[    0.000000] regulator: core version 0.5
[    0.000000] NET: Registered protocol family 16
[    0.000000] Found NAND on CS0
[    0.000000] Registering NAND on CS0
[    0.000000] Unable to get DVI reset GPIO
[    0.000000] hw perfevents: enabled with ARMv7 Cortex-A8 PMU driver, 5 counters available
[    0.000274] OMAP DMA hardware revision 4.0
[    0.415679] bio: create slab <bio-0> at 0
[    0.469024] SCSI subsystem initialized
[    0.482971] usbcore: registered new interface driver usbfs
[    0.490814] usbcore: registered new interface driver hub
[    0.495025] usbcore: registered new device driver usb
[    0.505828] i2c_omap i2c_omap.1: bus 1 rev3.12 at 2600 kHz
[    0.552673] twl4030: PIH (irq 7) chaining IRQs 368..375
[    0.553161] twl4030: power (irq 373) chaining IRQs 376..383
[    0.561676] twl4030: gpio (irq 368) chaining IRQs 384..401
[    0.588470] regulator: VUSB1V5: 1500 mV normal standby
[    0.602264] regulator: VUSB1V8: 1800 mV normal standby
[    0.615051] regulator: VUSB3V1: 3100 mV normal standby
[    0.644683] twl4030_usb twl4030_usb: Initialized TWL4030 USB module
[    0.662658] regulator: VMMC1: 1850 <--> 3150 mV at 3000 mV normal standby
[    0.675537] regulator: VDAC: 1800 mV normal standby
[    0.689483] regulator: VDVI: 1800 mV normal standby
[    0.706085] regulator: VSIM: 1800 <--> 3000 mV at 1800 mV normal standby
[    0.709747] i2c_omap i2c_omap.3: bus 3 rev3.12 at 100 kHz
[    0.736755] Advanced Linux Sound Architecture Driver Version 1.0.23.
[    0.757629] Switching to clocksource 32k_counter
[    1.133636] musb_hdrc: version 6.0, musb-dma, otg (peripheral+host), debug=0
[    1.139038] musb_hdrc musb_hdrc: USB OTG mode controller at fa0ab000 using DMA, IRQ 92
[    1.147277] NET: Registered protocol family 2
[    1.150573] IP route cache hash table entries: 2048 (order: 1, 8192 bytes)
[    1.159820] TCP established hash table entries: 8192 (order: 4, 65536 bytes)
[    1.160766] TCP bind hash table entries: 8192 (order: 6, 327680 bytes)
[    1.169006] TCP: Hash tables configured (established 8192 bind 8192)
[    1.169189] TCP reno registered
[    1.169311] UDP hash table entries: 128 (order: 1, 12288 bytes)
[    1.170135] UDP-Lite hash table entries: 128 (order: 1, 12288 bytes)
[    1.175537] NET: Registered protocol family 1
[    1.183532] RPC: Registered udp transport module.
[    1.183563] RPC: Registered tcp transport module.
[    1.183624] RPC: Registered tcp NFSv4.1 backchannel transport module.
[    1.196899] PMU: registered new PMU device of type 0
[    1.200012] NetWinder Floating Point Emulator V0.97 (double precision)
[    1.231811] VFS: Disk quotas dquot_6.5.2
[    1.232421] Dquot-cache hash table entries: 1024 (order 0, 4096 bytes)
[    1.256347] JFFS2 version 2.2. (NAND) © 2001-2006 Red Hat, Inc.
[    1.261993] msgmni has been set to 478
[    1.278167] alg: No test for stdrng (krng)
[    1.279144] io scheduler noop registered
[    1.279174] io scheduler deadline registered
[    1.280242] io scheduler cfq registered (default)
[    1.352478] OMAP DSS rev 2.0
[    1.353668] OMAP DISPC rev 3.0
[    1.354309] OMAP VENC rev 2
[    1.954925] Serial: 8250/16550 driver, 4 ports, IRQ sharing enabled
[    2.023956] serial8250.0: ttyS0 at MMIO 0x4806a000 (irq = 72) is a ST16654
[    2.058380] serial8250.1: ttyS1 at MMIO 0x4806c000 (irq = 73) is a ST16654
[    2.093322] serial8250.2: ttyS2 at MMIO 0x49020000 (irq = 74) is a ST16654
[    3.225219] console [ttyS2] enabled
[    3.494750] brd: module loaded
[    3.627441] loop: module loaded
[    3.684173] ehci_hcd: USB 2.0 'Enhanced' Host Controller (EHCI) Driver
[    3.692993] ehci-omap ehci-omap.0: OMAP-EHCI Host Controller
[    3.715576] ehci-omap ehci-omap.0: new USB bus registered, assigned bus number 1
[    3.726104] ehci-omap ehci-omap.0: irq 77, io mem 0x48064800
[    3.742553] ehci-omap ehci-omap.0: USB 2.0 started, EHCI 1.00
[    3.753845] usb usb1: New USB device found, idVendor=1d6b, idProduct=0002
[    3.760864] usb usb1: New USB device strings: Mfr=3, Product=2, SerialNumber=1
[    3.768249] usb usb1: Product: OMAP-EHCI Host Controller
[    3.773742] usb usb1: Manufacturer: Linux 2.6.34-next-20100524+ ehci_hcd
[    3.780517] usb usb1: SerialNumber: ehci-omap.0
[    3.811676] hub 1-0:1.0: USB hub found
[    3.817016] hub 1-0:1.0: 3 ports detected
[    3.870391] i2c /dev entries driver
[    3.901184] IR NEC protocol handler initialized
[    3.905792] IR RC5(x) protocol handler initialized
[    3.911102] IR RC6 protocol handler initialized
[    3.915832] IR JVC protocol handler initialized
[    3.920410] IR Sony protocol handler initialized
[    3.925659] Linux video capture interface: v2.00
[    3.939971] cpuidle: using governor ladder
[    3.944122] cpuidle: using governor menu
[    4.089355] No device for DAI omap-mcbsp-dai-0
[    4.094024] No device for DAI omap-mcbsp-dai-1
[    4.098541] No device for DAI omap-mcbsp-dai-2
[    4.103179] No device for DAI omap-mcbsp-dai-3
[    4.107666] No device for DAI omap-mcbsp-dai-4
[    4.112335] OMAP3 Beagle/Devkit8000 SoC init
[    4.133605] asoc: twl4030 <-> omap-mcbsp-dai-0 mapping ok
[    4.237731] ALSA device list:
[    4.240722]   #0: omap3beagle (twl4030)
[    4.246368] TCP cubic registered
[    4.249664] NET: Registered protocol family 17
[    4.256347] NET: Registered protocol family 15
[    4.263702] Power Management for TI OMAP3.
[    4.518066] VFP support v0.3: implementor 41 architecture 3 part 30 variant c rev 1
[    4.527282] mmc0: new SD card at address 0001
[    4.546081] mmcblk0: mmc0:0001 064MB 118 MiB 
[    4.559875]  mmcblk0:
[    4.569396]  p1 p2
[    4.609100] kmemleak: Kernel memory leak detector initialized
[    4.616729] omapfb omapfb: no driver for display
[    4.621643] omapfb omapfb: failed to setup omapfb
[    4.628204] kmemleak: Automatic memory scanning thread started
[    4.654388] regulator_init_complete: incomplete constraints, leaving VDVI on
[    4.662261] regulator_init_complete: incomplete constraints, leaving VDAC on
[    4.670959] drivers/rtc/hctosys.c: unable to open rtc device (rtc0)
[    4.715393] EXT3-fs: barriers not enabled
[    4.932281] EXT3-fs (mmcblk0p2): warning: mounting unchecked fs, running e2fsck is recommended
[    4.941253] kjournald starting.  Commit interval 5 seconds
[    4.956970] EXT3-fs (mmcblk0p2): using internal journal
[    4.962463] EXT3-fs (mmcblk0p2): recovery complete
[    4.978637] EXT3-fs (mmcblk0p2): mounted filesystem with writeback data mode
[    4.986999] VFS: Mounted root (ext3 filesystem) on device 179:2.
[    5.001312] devtmpfs: mounted
[    5.004943] Freeing init memory: 196K
[    5.093475] ------------[ cut here ]------------
[    5.098205] WARNING: at kernel/lockdep.c:3163 check_flags+0xcc/0x1dc()
[    5.104766] Modules linked in:
[    5.107910] [<c0040130>] (unwind_backtrace+0x0/0xf8) from [<c03d29cc>] (dump_stack+0x20/0x24)
[    5.116546] [<c03d29cc>] (dump_stack+0x20/0x24) from [<c006fce0>] (warn_slowpath_common+0x5c/0x74)
[    5.125579] [<c006fce0>] (warn_slowpath_common+0x5c/0x74) from [<c006fd24>] (warn_slowpath_null+0x2c/0x34)
[    5.135314] [<c006fd24>] (warn_slowpath_null+0x2c/0x34) from [<c009e840>] (check_flags+0xcc/0x1dc)
[    5.144378] [<c009e840>] (check_flags+0xcc/0x1dc) from [<c00a0b80>] (lockdep_trace_alloc+0x3c/0xfc)
[    5.153503] [<c00a0b80>] (lockdep_trace_alloc+0x3c/0xfc) from [<c0103d98>] (__kmalloc+0x6c/0x1fc)
[    5.162475] [<c0103d98>] (__kmalloc+0x6c/0x1fc) from [<c014a8d8>] (load_elf_binary+0x8cc/0x125c)
[    5.171356] [<c014a8d8>] (load_elf_binary+0x8cc/0x125c) from [<c010e03c>] (search_binary_handler+0x168/0x35c)
[    5.181365] [<c010e03c>] (search_binary_handler+0x168/0x35c) from [<c010f654>] (do_execve+0x224/0x320)
[    5.190765] [<c010f654>] (do_execve+0x224/0x320) from [<c003d7d4>] (kernel_execve+0x48/0x90)
[    5.199279] [<c003d7d4>] (kernel_execve+0x48/0x90) from [<c0039588>] (run_init_process+0x24/0x2c)
[    5.208251] [<c0039588>] (run_init_process+0x24/0x2c) from [<c003962c>] (init_post+0x9c/0xe4)
[    5.216857] [<c003962c>] (init_post+0x9c/0xe4) from [<c0008684>] (kernel_init+0x128/0x168)
[    5.225189] [<c0008684>] (kernel_init+0x128/0x168) from [<c003b10c>] (kernel_thread_exit+0x0/0x8)
[    5.234130] ---[ end trace b9d526d4d7022271 ]---
[    5.238800] possible reason: unannotated irqs-on.
[    5.243530] irq event stamp: 340905
[    5.247070] hardirqs last  enabled at (340904): [<c03d67b0>] _raw_spin_unlock_irqrestore+0x4c/0x78
[    5.256134] hardirqs last disabled at (340905): [<c0039b24>] __dabt_svc+0x64/0x80
[    5.263702] softirqs last  enabled at (340499): [<c0076da8>] __do_softirq+0x218/0x234
[    5.271606] softirqs last disabled at (340466): [<c0076e2c>] irq_exit+0x68/0xbc
init started: BusyBox v1.9.0 (2008-02-26 15:40:22 IST)
starting pid 429, tty '': '/etc/init.d/rcS'

    OMAP3EVM (v0.90) : System initialization...

    Kernel release : Linux 2.6.34-next-20100524+
    Kernel version : #56 PREEMPT Mon May 24 21:56:03 CST 2010

 Mounting /proc             : [SUCCESS]
 Mounting /sys              : [SUCCESS]
 Mounting /dev/pts          : [SUCCESS]
 Enabling hot-plug          : [SUCCESS]
 Populating /dev            : mkdir: cannot create directory '/dev/snd': File exists
[    6.570556] hub 1-0:1.0: __pm_runtime_suspend() from workqueue!
[    6.576568] hub 1-0:1.0: __pm_runtime_suspend() returns 0!
[    6.593933] usb usb1: __pm_runtime_suspend()!
[    6.598907] usb usb1: __pm_runtime_suspend() returns 0!
[SUCCESS]
 Mounting other filesystems : [SUCCESS]
 Starting syslogd           : Jan  1 00:00:10 OMAP3EVM syslog.info syslogd started: BusyBox v1.9.0
[SUCCESS]
 Starting telnetd           : 
[SUCCESS]

System initialization complete.

Please press Enter to activate this console. starting pid 452, tty '': '/bin/sh'

    Setting shell environment ...
    - Path
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    - Touchscreen

    Done!

[root@OMAP3EVM /]# 

Re: [RESEND PATCH] ARM: fix 'unannotated irqs-on' lockdep warning

[Russell King - ARM Linux]

On Mon, May 24, 2010 at 10:20:33PM +0800, Ming Lei wrote:
> On Mon, 24 May 2010 11:14:16 +0100
> Russell King - ARM Linux <linux@arm.linux.org.uk> wrote:
> 
> > Right, I see what the problem is now - it's all to do with threads
> > created with kernel_thread() confusing lockdep.
> > 
> > I'm of the opinion that all your changes in entry*.S are the wrong
> > way to fix this - not only does it add additional overhead where
> > none is really necessary, it adds additional complexity.
> > 
> > So, here's a patch to solve the warning you quoted.
> 
> No, your patch does not fix the issue, I still can see the lockdep
> warning after applying it against Linux 2.6.34-next-20100524.

No, my patch fixes the issue you raised in the dump.  This is a new
lockdep issue which is unrelated to the first dump.

What's wrong is:

commit 0d928b0b616d1c5c5fe76019a87cba171ca91633
Author: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Date:   Thu Aug 13 20:38:17 2009 +0200

    Complete irq tracing support for ARM

    Before this patch enabling and disabling irqs in assembler code and by
    the hardware wasn't tracked completly.

    I had to transpose two instructions in arch/arm/lib/bitops.h because
    restore_irqs doesn't preserve the flags with CONFIG_TRACE_IRQFLAGS=y

    Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
    Cc: Russell King <linux@arm.linux.org.uk>
    Cc: Peter Zijlstra <peterz@infradead.org>
    Cc: Ingo Molnar <mingo@redhat.com>

    Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>

which needs to be redone with a little more understanding, like the
following patch.  Note: you will need the previous patch as well,
which is separate because it addresses a *different* issue.

diff --git a/arch/arm/kernel/entry-armv.S b/arch/arm/kernel/entry-armv.S
index 7ee48e7..3fd7861 100644
--- a/arch/arm/kernel/entry-armv.S
+++ b/arch/arm/kernel/entry-armv.S
@@ -162,8 +162,6 @@ ENDPROC(__und_invalid)
 	@  r4 - orig_r0 (see pt_regs definition in ptrace.h)
 	@
 	stmia	r5, {r0 - r4}
-
-	asm_trace_hardirqs_off
 	.endm
 
 	.align	5
@@ -204,7 +202,7 @@ __dabt_svc:
 	@
 	@ IRQs off again before pulling preserved data off the stack
 	@
-	disable_irq
+	disable_irq_notrace
 
 	@
 	@ restore SPSR and restart the instruction
@@ -218,6 +216,9 @@ ENDPROC(__dabt_svc)
 __irq_svc:
 	svc_entry
 
+#ifdef CONFIG_TRACE_IRQFLAGS
+	bl	trace_hardirqs_off
+#endif
 #ifdef CONFIG_PREEMPT
 	get_thread_info tsk
 	ldr	r8, [tsk, #TI_PREEMPT]		@ get preempt count
@@ -291,7 +292,7 @@ __und_svc:
 	@
 	@ IRQs off again before pulling preserved data off the stack
 	@
-1:	disable_irq
+1:	disable_irq_notrace
 
 	@
 	@ restore SPSR and restart the instruction
@@ -327,7 +328,7 @@ __pabt_svc:
 	@
 	@ IRQs off again before pulling preserved data off the stack
 	@
-	disable_irq
+	disable_irq_notrace
 
 	@
 	@ restore SPSR and restart the instruction
@@ -393,8 +394,6 @@ ENDPROC(__pabt_svc)
 	@ Clear FP to mark the first stack frame
 	@
 	zero_fp
-
-	asm_trace_hardirqs_off
 	.endm
 
 	.macro	kuser_cmpxchg_check
@@ -465,9 +464,6 @@ __irq_usr:
  THUMB(	movne	r0, #0		)
  THUMB(	strne	r0, [r0]	)
 #endif
-#ifdef CONFIG_TRACE_IRQFLAGS
-	bl	trace_hardirqs_on
-#endif
 
 	mov	why, #0
 	b	ret_to_user

Re: [RESEND PATCH] ARM: fix 'unannotated irqs-on' lockdep warning

[Ming Lei]

2010/5/24 Russell King - ARM Linux <linux@arm.linux.org.uk>:
> which needs to be redone with a little more understanding, like the
> following patch.  Note: you will need the previous patch as well,
> which is separate because it addresses a *different* issue.

OK, the two patches do fix the 'unannotated irqs-on' lockdep warning.

Thanks,

-- 
Lei Ming