From 47348661c4e03480dc99a29c371b5fa930d1bb55 Mon Sep 17 00:00:00 2001 From: Philipp Zabel Date: Mon, 14 Apr 2014 23:53:18 +0200 Subject: [PATCH] imx-drm: ipu-dmfc: wait for FIFOs to run empty before disabling Disabling the DMFC module while there is still data in the FIFOs could cause the "new frame before end of frame" error state when the DMFC is enabled again. Signed-off-by: Philipp Zabel Signed-off-by: Russell King --- drivers/staging/imx-drm/ipu-v3/ipu-dmfc.c | 25 +++++++++++++++++++++-- 1 file changed, 23 insertions(+), 2 deletions(-) diff --git a/drivers/staging/imx-drm/ipu-v3/ipu-dmfc.c b/drivers/staging/imx-drm/ipu-v3/ipu-dmfc.c index 45213017fa4b..59f182b28fc1 100644 --- a/drivers/staging/imx-drm/ipu-v3/ipu-dmfc.c +++ b/drivers/staging/imx-drm/ipu-v3/ipu-dmfc.c @@ -28,7 +28,12 @@ #define DMFC_GENERAL1 0x0014 #define DMFC_GENERAL2 0x0018 #define DMFC_IC_CTRL 0x001c -#define DMFC_STAT 0x0020 +#define DMFC_WR_CHAN_ALT 0x0020 +#define DMFC_WR_CHAN_DEF_ALT 0x0024 +#define DMFC_DP_CHAN_ALT 0x0028 +#define DMFC_DP_CHAN_DEF_ALT 0x002c +#define DMFC_GENERAL1_ALT 0x0030 +#define DMFC_STAT 0x0034 #define DMFC_WR_CHAN_1_28 0 #define DMFC_WR_CHAN_2_41 8 @@ -133,6 +138,20 @@ int ipu_dmfc_enable_channel(struct dmfc_channel *dmfc) } EXPORT_SYMBOL_GPL(ipu_dmfc_enable_channel); +static void ipu_dmfc_wait_fifos(struct ipu_dmfc_priv *priv) +{ + unsigned long timeout = jiffies + msecs_to_jiffies(1000); + + while ((readl(priv->base + DMFC_STAT) & 0x02fff000) != 0x02fff000) { + if (time_after(jiffies, timeout)) { + dev_warn(priv->dev, + "Timeout waiting for DMFC FIFOs to clear\n"); + break; + } + cpu_relax(); + } +} + void ipu_dmfc_disable_channel(struct dmfc_channel *dmfc) { struct ipu_dmfc_priv *priv = dmfc->priv; @@ -141,8 +160,10 @@ void ipu_dmfc_disable_channel(struct dmfc_channel *dmfc) priv->use_count--; - if (!priv->use_count) + if (!priv->use_count) { + ipu_dmfc_wait_fifos(priv); ipu_module_disable(priv->ipu, IPU_CONF_DMFC_EN); + } if (priv->use_count < 0) priv->use_count = 0; -- 2.20.1