[PATCH] dma-debug: Make locking to work for RT

From: Pankaj Gupta
Date: Thu Apr 13 2017 - 02:41:29 EST


Interrupt enable/disabled with spinlock is not a valid
implementation for RT as it can make executing task to
sleep from a non-sleepable context. So, converting it
to spin_lock_irq[save, restore].

Signed-off-by: Pankaj Gupta <pagupta@xxxxxxxxxx>
---
lib/dma-debug.c | 8 ++------
1 file changed, 2 insertions(+), 6 deletions(-)

diff --git a/lib/dma-debug.c b/lib/dma-debug.c
index b157b46..fe4d50c 100644
--- a/lib/dma-debug.c
+++ b/lib/dma-debug.c
@@ -942,21 +942,17 @@ static int device_dma_allocations(struct device *dev, struct dma_debug_entry **o
unsigned long flags;
int count = 0, i;

- local_irq_save(flags);
-
for (i = 0; i < HASH_SIZE; ++i) {
- spin_lock(&dma_entry_hash[i].lock);
+ spin_lock_irqsave(&dma_entry_hash[i].lock, flags);
list_for_each_entry(entry, &dma_entry_hash[i].list, list) {
if (entry->dev == dev) {
count += 1;
*out_entry = entry;
}
}
- spin_unlock(&dma_entry_hash[i].lock);
+ spin_unlock_irqrestore(&dma_entry_hash[i].lock, flags);
}

- local_irq_restore(flags);
-
return count;
}

--
2.7.4