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

From: Richard Zhao
Date: Sat Dec 31 2011 - 22:30:17 EST

From: Haitao Zhang <minipanda@xxxxxxxxxxxxxx>

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@xxxxxxxxxx>
Signed-off-by: Eric Miao <eric.miao@xxxxxxxxxx>
Signed-off-by: Richard Zhao <richard.zhao@xxxxxxxxxx>
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;

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