[PATCH] drm/stm: ltdc: reset controller to avoid partial refresh

From: Yannick FertrÃ
Date: Wed Apr 03 2019 - 05:24:32 EST


Display controller reset must be done as soon as possible after enable
the clock to avoid partial refresh on screen.

Signed-off-by: Yannick Fertrà <yannick.fertre@xxxxxx>
---
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