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From: Philipp Zabel <p.zabel@pengutronix.de>
To: devel@driverdev.osuosl.org, Russell King <rmk+kernel@arm.linux.org.uk>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org,
	kernel@pengutronix.de, Philipp Zabel <p.zabel@pengutronix.de>
Subject: [PATCH v2 3/8] imx-drm: ipu-dmfc: Wait for FIFOs to run empty before disabling
Date: Mon, 14 Apr 2014 23:53:18 +0200	[thread overview]
Message-ID: <1397512403-19622-4-git-send-email-p.zabel@pengutronix.de> (raw)
In-Reply-To: <1397512403-19622-1-git-send-email-p.zabel@pengutronix.de>

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 <p.zabel@pengutronix.de>
---
 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 4521301..59f182b 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;
-- 
1.9.1


WARNING: multiple messages have this Message-ID (diff)
From: Philipp Zabel <p.zabel@pengutronix.de>
To: devel@driverdev.osuosl.org, Russell King <rmk+kernel@arm.linux.org.uk>
Cc: kernel@pengutronix.de,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org
Subject: [PATCH v2 3/8] imx-drm: ipu-dmfc: Wait for FIFOs to run empty before disabling
Date: Mon, 14 Apr 2014 23:53:18 +0200	[thread overview]
Message-ID: <1397512403-19622-4-git-send-email-p.zabel@pengutronix.de> (raw)
In-Reply-To: <1397512403-19622-1-git-send-email-p.zabel@pengutronix.de>

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 <p.zabel@pengutronix.de>
---
 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 4521301..59f182b 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;
-- 
1.9.1

  parent reply	other threads:[~2014-04-14 21:53 UTC|newest]

Thread overview: 22+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-04-14 21:53 [PATCH v2 0/8] Reorder i.MX IPU display enable/disable sequence Philipp Zabel
2014-04-14 21:53 ` Philipp Zabel
2014-04-14 21:53 ` [PATCH v2 1/8] imx-drm: ipu-common: add ipu_map_irq to request non-IDMAC interrupts Philipp Zabel
2014-04-14 21:53   ` Philipp Zabel
2014-04-14 21:53 ` [PATCH v2 2/8] imx-drm: ipu-common: Add helpers to check for a busy IDMAC channel and to busywait for an interrupt Philipp Zabel
2014-04-14 21:53   ` Philipp Zabel
2014-04-14 21:53 ` Philipp Zabel [this message]
2014-04-14 21:53   ` [PATCH v2 3/8] imx-drm: ipu-dmfc: Wait for FIFOs to run empty before disabling Philipp Zabel
2014-04-14 21:53 ` [PATCH v2 4/8] imx-drm: ipu-dc: Wait for DC_FC_1 / DP_SF_END interrupt Philipp Zabel
2014-04-14 21:53   ` Philipp Zabel
2014-04-14 21:53 ` [PATCH v2 5/8] imx-drm: ipu-dp: Split disabling the DP foreground channel from disabling the DP module Philipp Zabel
2014-04-14 21:53   ` Philipp Zabel
2014-04-14 21:53 ` [PATCH v2 6/8] imx-drm: imx-dp: When disabling the DP foreground channel, wait until the DP background channel is finished before disabling the IDMAC channel Philipp Zabel
2014-04-14 21:53   ` Philipp Zabel
2014-04-14 21:53 ` [PATCH v2 7/8] imx-drm: ipuv3-crtc: Change display enable/disable order Philipp Zabel
2014-04-14 21:53   ` Philipp Zabel
2014-04-14 21:53 ` [PATCH v2 8/8] imx-drm: ipu-dc: Disable DC module when not in use Philipp Zabel
2014-04-14 21:53   ` Philipp Zabel
2014-04-14 22:18 ` [PATCH v2 0/8] Reorder i.MX IPU display enable/disable sequence Russell King - ARM Linux
2014-04-14 22:18   ` Russell King - ARM Linux
2014-04-18 10:13 ` Russell King - ARM Linux
2014-04-18 10:13   ` Russell King - ARM Linux

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