From 25be2874570427849b566e76f355758b4d0e9c7f Mon Sep 17 00:00:00 2001
From: Maxime Ripard <maxime@cerno.tech>
Date: Thu, 3 Sep 2020 10:01:46 +0200
Subject: drm/vc4: hdmi: Switch to blank pixels when disabled
Git-commit: 81d830137bdb462ca0bef91ba1f187d7be5d0081
Patch-mainline: v5.10-rc1
References: jsc#SLE-15318
In order to avoid pixels getting stuck in an unflushable FIFO, we need when
we disable the HDMI controller to switch away from getting our pixels from
the pixelvalve and instead use blank pixels, and switch back to the
pixelvalve when we enable the HDMI controller.
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
Tested-by: Chanwoo Choi <cw00.choi@samsung.com>
Tested-by: Hoegeun Kwon <hoegeun.kwon@samsung.com>
Tested-by: Stefan Wahren <stefan.wahren@i2se.com>
Reviewed-by: Dave Stevenson <dave.stevenson@raspberrypi.com>
Link: https://patchwork.freedesktop.org/patch/msgid/fde3efb1ad79f4476a73d310cbba3ec07dc6dabe.1599120059.git-series.maxime@cerno.tech
Signed-off-by: Patrik Jakobsson <pjakobsson@suse.de>
---
drivers/gpu/drm/vc4/vc4_hdmi.c | 9 +++++++++
drivers/gpu/drm/vc4/vc4_regs.h | 3 +++
2 files changed, 12 insertions(+)
diff --git a/drivers/gpu/drm/vc4/vc4_hdmi.c b/drivers/gpu/drm/vc4/vc4_hdmi.c
index a2de94c8d3c5..4a8843a79f25 100644
--- a/drivers/gpu/drm/vc4/vc4_hdmi.c
+++ b/drivers/gpu/drm/vc4/vc4_hdmi.c
@@ -325,6 +325,12 @@ static void vc4_hdmi_encoder_post_crtc_disable(struct drm_encoder *encoder)
struct vc4_hdmi *vc4_hdmi = encoder_to_vc4_hdmi(encoder);
HDMI_WRITE(HDMI_RAM_PACKET_CONFIG, 0);
+
+ HDMI_WRITE(HDMI_VID_CTL, HDMI_READ(HDMI_VID_CTL) |
+ VC4_HD_VID_CTL_CLRRGB | VC4_HD_VID_CTL_CLRSYNC);
+
+ HDMI_WRITE(HDMI_VID_CTL,
+ HDMI_READ(HDMI_VID_CTL) | VC4_HD_VID_CTL_BLANKPIX);
}
static void vc4_hdmi_encoder_post_crtc_powerdown(struct drm_encoder *encoder)
@@ -563,6 +569,9 @@ static void vc4_hdmi_encoder_post_crtc_enable(struct drm_encoder *encoder)
(vsync_pos ? 0 : VC4_HD_VID_CTL_VSYNC_LOW) |
(hsync_pos ? 0 : VC4_HD_VID_CTL_HSYNC_LOW));
+ HDMI_WRITE(HDMI_VID_CTL,
+ HDMI_READ(HDMI_VID_CTL) & ~VC4_HD_VID_CTL_BLANKPIX);
+
if (vc4_encoder->hdmi_monitor) {
HDMI_WRITE(HDMI_SCHEDULER_CONTROL,
HDMI_READ(HDMI_SCHEDULER_CONTROL) |
diff --git a/drivers/gpu/drm/vc4/vc4_regs.h b/drivers/gpu/drm/vc4/vc4_regs.h
index d1e8961edaa0..30af52b406f1 100644
--- a/drivers/gpu/drm/vc4/vc4_regs.h
+++ b/drivers/gpu/drm/vc4/vc4_regs.h
@@ -723,6 +723,9 @@
# define VC4_HD_VID_CTL_FRAME_COUNTER_RESET BIT(29)
# define VC4_HD_VID_CTL_VSYNC_LOW BIT(28)
# define VC4_HD_VID_CTL_HSYNC_LOW BIT(27)
+# define VC4_HD_VID_CTL_CLRSYNC BIT(24)
+# define VC4_HD_VID_CTL_CLRRGB BIT(23)
+# define VC4_HD_VID_CTL_BLANKPIX BIT(18)
# define VC4_HD_CSC_CTL_ORDER_MASK VC4_MASK(7, 5)
# define VC4_HD_CSC_CTL_ORDER_SHIFT 5
--
2.29.2