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gpu: ipu-v3: ipu-dmfc: Protect function ipu_dmfc_init_channel() with mutex 

To avoid race condition issue, we should protect the function
ipu_dmfc_init_channel() with the mutex dmfc->priv->mutex, since it
configures the register DMFC_GENERAL1 at runtime which contains
several control bits for various display channels.  This matches
better with fine grained locking logic in upper layer.

Signed-off-by: Liu Ying <gnuiyl@gmail.com>
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
This commit is contained in:
Liu Ying 2016-03-14 16:10:08 +08:00 committed by Philipp Zabel
parent 1cc9daea2a
commit 32c26a56af
1 changed files with 4 additions and 0 deletions
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4
drivers/gpu/ipu-v3/ipu-dmfc.c
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@ -355,6 +355,8 @@ int ipu_dmfc_init_channel(struct dmfc_channel *dmfc, int width)
struct ipu_dmfc_priv *priv = dmfc->priv;
u32 dmfc_gen1;
mutex_lock(&priv->mutex);
dmfc_gen1 = readl(priv->base + DMFC_GENERAL1);
if ((dmfc->slots * 64 * 4) / width > dmfc->data->max_fifo_lines)
@ -364,6 +366,8 @@ int ipu_dmfc_init_channel(struct dmfc_channel *dmfc, int width)
writel(dmfc_gen1, priv->base + DMFC_GENERAL1);
mutex_unlock(&priv->mutex);
return 0;
}
EXPORT_SYMBOL_GPL(ipu_dmfc_init_channel);