[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 at karo-electronics.de> wrote:
> Hi,
>
> Dong Aisheng wrote:
>> On Mon, Jan 13, 2014 at 8:04 PM, Peter Zijlstra <peterz at 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
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