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From:   Sasha Levin <sashal@kernel.org>
To:     stable@vger.kernel.org, linux-kernel@vger.kernel.org
Cc:     Marek Vasut <marex@denx.de>,
        Steve Longerbeam <steve_longerbeam@mentor.com>,
        Philipp Zabel <p.zabel@pengutronix.de>,
        Sasha Levin <sashal@kernel.org>
Subject: [PATCH AUTOSEL 4.9 38/98] gpu: ipu-v3: Fix CSI selection for VDIC
Date:   Thu, 25 Oct 2018 10:13:23 -0400
Message-Id: <20181025141423.213774-38-sashal@kernel.org>
In-Reply-To: <20181025141423.213774-1-sashal@kernel.org>
References: <20181025141423.213774-1-sashal@kernel.org>
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

From: Marek Vasut <marex@denx.de>

[ Upstream commit b7dfee2433576f1f030cb84cdb04b70f36554992 ]

The description of the CSI_SEL bit in the i.MX6 reference manual is
incorrect. It states "This bit defines which CSI is the input to the
IC. This bit is effective only if IC_INPUT is bit cleared".

From experiment it was found this is in fact not correct. The CSI_SEL
bit selects which CSI is input to _both_ the VDIC _and_ the IC. If the
IC_INPUT bit is set so that the IC is receiving from the VDIC, the IC
ignores the CSI_SEL bit, but CSI_SEL still selects which CSI the VDIC
receives from in that case.

Signed-off-by: Marek Vasut <marex@denx.de>
Signed-off-by: Steve Longerbeam <steve_longerbeam@mentor.com>
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/gpu/ipu-v3/ipu-common.c | 15 ++++++++-------
 1 file changed, 8 insertions(+), 7 deletions(-)

diff --git a/drivers/gpu/ipu-v3/ipu-common.c b/drivers/gpu/ipu-v3/ipu-common.c
index b9539f7c5e9a..99c813a4ec1f 100644
--- a/drivers/gpu/ipu-v3/ipu-common.c
+++ b/drivers/gpu/ipu-v3/ipu-common.c
@@ -715,15 +715,16 @@ void ipu_set_ic_src_mux(struct ipu_soc *ipu, int csi_id, bool vdi)
 	spin_lock_irqsave(&ipu->lock, flags);
 
 	val = ipu_cm_read(ipu, IPU_CONF);
-	if (vdi) {
+	if (vdi)
 		val |= IPU_CONF_IC_INPUT;
-	} else {
+	else
 		val &= ~IPU_CONF_IC_INPUT;
-		if (csi_id == 1)
-			val |= IPU_CONF_CSI_SEL;
-		else
-			val &= ~IPU_CONF_CSI_SEL;
-	}
+
+	if (csi_id == 1)
+		val |= IPU_CONF_CSI_SEL;
+	else
+		val &= ~IPU_CONF_CSI_SEL;
+
 	ipu_cm_write(ipu, val, IPU_CONF);
 
 	spin_unlock_irqrestore(&ipu->lock, flags);
-- 
2.17.1