imx-drm: imx-dp: when disabling the DP foreground channel, wait until the DP...

imx-drm: imx-dp: when disabling the DP foreground channel, wait until the DP background channel is finished before disabling the IDMAC channel
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

drivers/staging/imx-drm/ipu-v3/ipu-dp.c

@@ -277,6 +277,9 @@ void ipu_dp_disable_channel(struct ipu_dp *dp)
 	writel(0, flow->base + DP_FG_POS);
 	ipu_srm_dp_sync_update(priv->ipu);
 
+	if (ipu_idmac_channel_busy(priv->ipu, IPUV3_CHANNEL_MEM_BG_SYNC))
+		ipu_wait_interrupt(priv->ipu, IPU_IRQ_DP_SF_END, 50);
+
 	mutex_unlock(&priv->mutex);
 }
 EXPORT_SYMBOL_GPL(ipu_dp_disable_channel);