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

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

[Dmitry Osipenko]

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 <dmitry.osipenko@collabora.com>
---
 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

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

[Vinod Koul]

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