Commit 32c26a56 authored Mar 14, 2016 by Liu Ying Committed by Philipp Zabel Mar 31, 2016

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>

parent 1cc9daea

drivers/gpu/ipu-v3/ipu-dmfc.c

+4 −0

Original line number	Diff line number	Diff line
		@@ -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);