[PATCH] drm/stm: ltdc: rework reset sequence

From: Yannick Fertre
Date: Fri Jun 29 2018 - 07:22:55 EST


Reset must be properly assert before deassert.
This is important if there is an early boot splash screen
before the kernel start up.

Signed-off-by: Yannick Fertre <yannick.fertre@xxxxxx>
---
drivers/gpu/drm/stm/ltdc.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/stm/ltdc.c b/drivers/gpu/drm/stm/ltdc.c
index 96d20c2..8f4606d 100644
--- a/drivers/gpu/drm/stm/ltdc.c
+++ b/drivers/gpu/drm/stm/ltdc.c
@@ -1130,8 +1130,11 @@ int ltdc_load(struct drm_device *ddev)
}
}

- if (!IS_ERR(rstc))
+ if (!IS_ERR(rstc)) {
+ reset_control_assert(rstc);
+ usleep_range(10, 20);
reset_control_deassert(rstc);
+ }

/* Disable interrupts */
reg_clear(ldev->regs, LTDC_IER,
--
1.9.1