2022-05-23 06:34:22

by Dmitry Osipenko

Subject: [PATCH v1] dmaengine: pl330: Fix lockdep warning about non-static key

The DEFINE_SPINLOCK() macro shouldn't be used for dynamically allocated
spinlocks. The lockdep warns about this and disables locking validator.
Fix the warning by making lock static.

INFO: trying to register non-static key.
The code is fine but needs lockdep annotation, or maybe
you didn't initialize this object before use?
turning off the locking correctness validator.
Hardware name: Radxa ROCK Pi 4C (DT)
Call trace:
dump_backtrace.part.0+0xcc/0xe0
show_stack+0x18/0x6c
dump_stack_lvl+0x8c/0xb8
dump_stack+0x18/0x34
register_lock_class+0x4a8/0x4cc
__lock_acquire+0x78/0x20cc
lock_acquire.part.0+0xe0/0x230
lock_acquire+0x68/0x84
_raw_spin_lock_irqsave+0x84/0xc4
add_desc+0x44/0xc0
pl330_get_desc+0x15c/0x1d0
pl330_prep_dma_cyclic+0x100/0x270
snd_dmaengine_pcm_trigger+0xec/0x1c0
dmaengine_pcm_trigger+0x18/0x24
...

Fixes: e588710311ee ("dmaengine: pl330: fix descriptor allocation fail")
Signed-off-by: Dmitry Osipenko <[email protected]>
---
drivers/dma/pl330.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/dma/pl330.c b/drivers/dma/pl330.c
index 858400e42ec0..09915a5cba3e 100644
--- a/drivers/dma/pl330.c
+++ b/drivers/dma/pl330.c
@@ -2589,7 +2589,7 @@ static struct dma_pl330_desc *pl330_get_desc(struct dma_pl330_chan *pch)

/* If the DMAC pool is empty, alloc new */
if (!desc) {
- DEFINE_SPINLOCK(lock);
+ static DEFINE_SPINLOCK(lock);
LIST_HEAD(pool);

if (!add_desc(&pool, &lock, GFP_ATOMIC, 1))
--
2.35.3

2022-07-06 05:22:34

by Vinod Koul

Subject: Re: [PATCH v1] dmaengine: pl330: Fix lockdep warning about non-static key

On 20-05-22, 21:14, Dmitry Osipenko wrote:
> The DEFINE_SPINLOCK() macro shouldn't be used for dynamically allocated
> spinlocks. The lockdep warns about this and disables locking validator.
> Fix the warning by making lock static.
>
> INFO: trying to register non-static key.
> The code is fine but needs lockdep annotation, or maybe
> you didn't initialize this object before use?
> turning off the locking correctness validator.
> Hardware name: Radxa ROCK Pi 4C (DT)
> Call trace:
> dump_backtrace.part.0+0xcc/0xe0
> show_stack+0x18/0x6c
> dump_stack_lvl+0x8c/0xb8
> dump_stack+0x18/0x34
> register_lock_class+0x4a8/0x4cc
> __lock_acquire+0x78/0x20cc
> lock_acquire.part.0+0xe0/0x230
> lock_acquire+0x68/0x84
> _raw_spin_lock_irqsave+0x84/0xc4
> add_desc+0x44/0xc0
> pl330_get_desc+0x15c/0x1d0
> pl330_prep_dma_cyclic+0x100/0x270
> snd_dmaengine_pcm_trigger+0xec/0x1c0
> dmaengine_pcm_trigger+0x18/0x24
> ...

Applied, thanks

--
~Vinod