linux-kernel - [PATCH v2 12/15] drm: sprd: always initialize DPU and DSI registers

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Message-Id: <20250722-ums9230-drm-v2-12-054276ec213d@abscue.de>
Date: Tue, 22 Jul 2025 16:41:14 +0200
From: Otto Pflüger <otto.pflueger@...cue.de>
To: David Airlie <airlied@...il.com>, Simona Vetter <simona@...ll.ch>, 
 Maarten Lankhorst <maarten.lankhorst@...ux.intel.com>, 
 Maxime Ripard <mripard@...nel.org>, Thomas Zimmermann <tzimmermann@...e.de>, 
 Rob Herring <robh@...nel.org>, Krzysztof Kozlowski <krzk+dt@...nel.org>, 
 Conor Dooley <conor+dt@...nel.org>, Orson Zhai <orsonzhai@...il.com>, 
 Baolin Wang <baolin.wang@...ux.alibaba.com>, 
 Chunyan Zhang <zhang.lyra@...il.com>, Kevin Tang <kevin.tang@...soc.com>
Cc: dri-devel@...ts.freedesktop.org, devicetree@...r.kernel.org, 
 linux-kernel@...r.kernel.org, 
 Otto Pflüger <otto.pflueger@...cue.de>
Subject: [PATCH v2 12/15] drm: sprd: always initialize DPU and DSI
 registers

When the Unisoc DRM driver is initialized for the first time to display
an image on the screen, reinitialize the display properly instead of
relying on the bootloader.

Signed-off-by: Otto Pflüger <otto.pflueger@...cue.de>
---
 drivers/gpu/drm/sprd/sprd_dpu.c | 8 ++++++++
 drivers/gpu/drm/sprd/sprd_dsi.c | 1 -
 2 files changed, 8 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/sprd/sprd_dpu.c b/drivers/gpu/drm/sprd/sprd_dpu.c
index 978d4947e1bc5cd5b13b1f25719268fa08b77297..b946d015133db44d2d3d0b18803ed887b2b7ae2e 100644
--- a/drivers/gpu/drm/sprd/sprd_dpu.c
+++ b/drivers/gpu/drm/sprd/sprd_dpu.c
@@ -456,6 +456,14 @@ static void sprd_dpu_init(struct sprd_dpu *dpu)
 	}
 
 	writel(int_mask, ctx->base + REG_DPU_INT_EN);
+
+	/*
+	 * The DPU is usually enabled by the bootloader to show
+	 * a splash screen. Stop it here when the kernel initializes
+	 * the display.
+	 */
+	if (!ctx->stopped)
+		sprd_dpu_stop(dpu);
 }
 
 static void sprd_dpu_fini(struct sprd_dpu *dpu)
diff --git a/drivers/gpu/drm/sprd/sprd_dsi.c b/drivers/gpu/drm/sprd/sprd_dsi.c
index 2af4273a6c73185084290c9d14b8ac18914d514b..7186d11bbdc753f52aba18995f4863b572f4fecb 100644
--- a/drivers/gpu/drm/sprd/sprd_dsi.c
+++ b/drivers/gpu/drm/sprd/sprd_dsi.c
@@ -954,7 +954,6 @@ static int sprd_dsi_context_init(struct sprd_dsi *dsi,
 	ctx->max_rd_time = 6000;
 	ctx->int0_mask = 0xffffffff;
 	ctx->int1_mask = 0xffffffff;
-	ctx->enabled = true;
 
 	return 0;
 }

-- 
2.50.0