Commit 6a5cd60b authored May 03, 2017 by Pankaj Gupta Committed by Linus Torvalds May 03, 2017

lib/dma-debug.c: make locking work for RT

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

Link: http://lkml.kernel.org/r/1492065666-3816-1-git-send-email-pagupta@redhat.com


Signed-off-by: Pankaj Gupta <pagupta@redhat.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Cc: Vinod Koul <vinod.koul@intel.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Ville Syrjl <ville.syrjala@linux.intel.com>
Cc: Miles Chen <miles.chen@mediatek.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Joerg Roedel <jroedel@suse.de>
Cc: Stanislaw Gruszka <sgruszka@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

parent 46f0537b

lib/dma-debug.c

+2 −6

Original line number	Diff line number	Diff line
		@@ -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;
		}

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