[PATCH v5 24/80] drm/vc4: hvs: Make sure our channel is reset

[Maxime Ripard]

In order to clear our intermediate FIFOs that might end up with a stale
pixel, let's make sure our FIFO channel is reset every time our channel is
setup.

Reviewed-by: Dave Stevenson <dave.stevenson at raspberrypi.com>
Tested-by: Chanwoo Choi <cw00.choi at samsung.com>
Tested-by: Hoegeun Kwon <hoegeun.kwon at samsung.com>
Tested-by: Stefan Wahren <stefan.wahren at i2se.com>
Signed-off-by: Maxime Ripard <maxime at cerno.tech>
---
 drivers/gpu/drm/vc4/vc4_hvs.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/gpu/drm/vc4/vc4_hvs.c b/drivers/gpu/drm/vc4/vc4_hvs.c
index efaae60bb323..0f56a7b57916 100644
--- a/drivers/gpu/drm/vc4/vc4_hvs.c
+++ b/drivers/gpu/drm/vc4/vc4_hvs.c
@@ -205,6 +205,10 @@ static int vc4_hvs_init_channel(struct vc4_dev *vc4, struct drm_crtc *crtc,
 	u32 dispbkgndx;
 	u32 dispctrl;
 
+	HVS_WRITE(SCALER_DISPCTRLX(chan), 0);
+	HVS_WRITE(SCALER_DISPCTRLX(chan), SCALER_DISPCTRLX_RESET);
+	HVS_WRITE(SCALER_DISPCTRLX(chan), 0);
+
 	/* Turn on the scaler, which will wait for vstart to start
 	 * compositing.
 	 * When feeding the transposer, we should operate in oneshot
-- 
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