Re: [PATCH] CMA: correct unlock target

From: Michal Nazarewicz
Date: Thu May 29 2014 - 19:49:01 EST


On Thu, May 29 2014, Joonsoo Kim <iamjoonsoo.kim@xxxxxxx> wrote:
> 'cma: Remove potential deadlock situation' introduces per cma area mutex
> for bitmap management. It is good, but there is one mistake. When we
> can't find appropriate area in bitmap, we release cma_mutex global lock
> rather than cma->lock and this is a bug. So fix it.
>
> Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@xxxxxxx>

Acked-by: Michal Nazarewicz <mina86@xxxxxxxxxx>

> diff --git a/drivers/base/dma-contiguous.c b/drivers/base/dma-contiguous.c
> index 6f6bffc..83969f8 100644
> --- a/drivers/base/dma-contiguous.c
> +++ b/drivers/base/dma-contiguous.c
> @@ -331,7 +331,7 @@ struct page *dma_alloc_from_contiguous(struct device *dev, int count,
> pageno = bitmap_find_next_zero_area(cma->bitmap, cma->count,
> start, count, mask);
> if (pageno >= cma->count) {
> - mutex_unlock(&cma_mutex);
> + mutex_unlock(&cma->lock);
> break;
> }
> bitmap_set(cma->bitmap, pageno, count);
> --
> 1.7.9.5

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Best regards, _ _
.o. | Liege of Serenely Enlightened Majesty of o' \,=./ `o
..o | Computer Science, MichaÅ âmina86â Nazarewicz (o o)
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