[PATCH] dma/imx-sdma: save irq flags when use spin_lock in sdma_tx_submit

[s.hauer@pengutronix.de (Sascha Hauer)]

On Sun, Jan 01, 2012 at 11:30:06AM +0800, Richard Zhao wrote:
> From: Haitao Zhang <minipanda@linuxrobot.org>

Acked-by: Sascha Hauer <s.hauer@pengutronix.de>

> 
> mx53_loco: fix deadlock report from sdma_tx_submit() during boot
> 
> BugLink: http://bugs.launchpad.net/bugs/878701
> 
> Adjust to use spin_lock_irqsave()/spin_unlock_irqresotre(), so to
> make it safe when called from interrupt context.
> 
> Signed-off-by: Haitao Zhang <haitao.zhang@linaro.org>
> Signed-off-by: Eric Miao <eric.miao@linaro.org>
> Signed-off-by: Richard Zhao <richard.zhao@linaro.org>
> ---
>  drivers/dma/imx-sdma.c |    5 +++--
>  1 files changed, 3 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/dma/imx-sdma.c b/drivers/dma/imx-sdma.c
> index f993955..2b7a88b 100644
> --- a/drivers/dma/imx-sdma.c
> +++ b/drivers/dma/imx-sdma.c
> @@ -832,17 +832,18 @@ static struct sdma_channel *to_sdma_chan(struct dma_chan *chan)
>  
>  static dma_cookie_t sdma_tx_submit(struct dma_async_tx_descriptor *tx)
>  {
> +	unsigned long flags;
>  	struct sdma_channel *sdmac = to_sdma_chan(tx->chan);
>  	struct sdma_engine *sdma = sdmac->sdma;
>  	dma_cookie_t cookie;
>  
> -	spin_lock_irq(&sdmac->lock);
> +	spin_lock_irqsave(&sdmac->lock, flags);
>  
>  	cookie = sdma_assign_cookie(sdmac);
>  
>  	sdma_enable_channel(sdma, sdmac->channel);
>  
> -	spin_unlock_irq(&sdmac->lock);
> +	spin_unlock_irqrestore(&sdmac->lock, flags);
>  
>  	return cookie;
>  }
> -- 
> 1.7.4.1
> 
> 

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