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From:   =?UTF-8?q?Yannick=20Fertr=C3=A9?= <yannick.fertre@st.com>
To:     Yannick Fertre <yannick.fertre@st.com>,
        Philippe Cornu <philippe.cornu@st.com>,
        Benjamin Gaignard <benjamin.gaignard@st.com>,
        Vincent Abriou <vincent.abriou@st.com>,
        David Airlie <airlied@linux.ie>,
        Daniel Vetter <daniel@ffwll.ch>,
        Maxime Coquelin <mcoquelin.stm32@gmail.com>,
        Alexandre Torgue <alexandre.torgue@st.com>,
        <dri-devel@lists.freedesktop.org>,
        <linux-stm32@st-md-mailman.stormreply.com>,
        <linux-arm-kernel@lists.infradead.org>,
        <linux-kernel@vger.kernel.org>
Subject: [PATCH] drm/stm: ltdc: reset controller to avoid partial refresh
Date:   Wed, 3 Apr 2019 11:24:13 +0200
Message-ID: <1554283453-2879-1-git-send-email-yannick.fertre@st.com>
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Sender: linux-kernel-owner@vger.kernel.org
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Display controller reset must be done as soon as possible after enable
the clock to avoid partial refresh on screen.

Signed-off-by: Yannick Fertré <yannick.fertre@st.com>
---
 drivers/gpu/drm/stm/ltdc.c | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/drivers/gpu/drm/stm/ltdc.c b/drivers/gpu/drm/stm/ltdc.c
index 32fd6a3..7bbe61c 100644
--- a/drivers/gpu/drm/stm/ltdc.c
+++ b/drivers/gpu/drm/stm/ltdc.c
@@ -1134,6 +1134,12 @@ int ltdc_load(struct drm_device *ddev)
 		return -ENODEV;
 	}
 
+	if (!IS_ERR(rstc)) {
+		reset_control_assert(rstc);
+		usleep_range(10, 20);
+		reset_control_deassert(rstc);
+	}
+
 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 	ldev->regs = devm_ioremap_resource(dev, res);
 	if (IS_ERR(ldev->regs)) {
@@ -1156,12 +1162,6 @@ int ltdc_load(struct drm_device *ddev)
 		}
 	}
 
-	if (!IS_ERR(rstc)) {
-		reset_control_assert(rstc);
-		usleep_range(10, 20);
-		reset_control_deassert(rstc);
-	}
-
 	/* Disable interrupts */
 	reg_clear(ldev->regs, LTDC_IER,
 		  IER_LIE | IER_RRIE | IER_FUIE | IER_TERRIE);
-- 
2.7.4