[PATCH] dma-debug: Avoid spinlock recursion when disabling dma-debug

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[PATCH] dma-debug: Avoid spinlock recursion when disabling dma-debug

Ville Syrjälä-2
From: Ville Syrjälä <[hidden email]>

With netconsole (at least) the pr_err("... disabling\n") call
can recurse back into the dma-debug code, where it'll try to
grab free_entries_lock again. Avoid the problem by doing
the printk after dropping the lock.

Cc: [hidden email]
Cc: Andrew Morton <[hidden email]>
Signed-off-by: Ville Syrjälä <[hidden email]>
---
 lib/dma-debug.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lib/dma-debug.c b/lib/dma-debug.c
index 4a1515f4b452..51a76af25c66 100644
--- a/lib/dma-debug.c
+++ b/lib/dma-debug.c
@@ -657,9 +657,9 @@ static struct dma_debug_entry *dma_entry_alloc(void)
  spin_lock_irqsave(&free_entries_lock, flags);
 
  if (list_empty(&free_entries)) {
- pr_err("DMA-API: debugging out of memory - disabling\n");
  global_disable = true;
  spin_unlock_irqrestore(&free_entries_lock, flags);
+ pr_err("DMA-API: debugging out of memory - disabling\n");
  return NULL;
  }
 
--
2.7.4