From 9ab0414c4c930fa0bf75d0e76c37e9857a5df099 Mon Sep 17 00:00:00 2001
From: Maxime Ripard <maxime@cerno.tech>
Date: Mon, 28 Mar 2022 17:36:58 +0200
Subject: drm/vc4: kms: Warn if we have an incompatible muxing setup
Git-commit: 457e5184b9e0e14b26044c7fed5940bcbe7698a7
Patch-mainline: v5.19-rc1
References: jsc#PED-1166 jsc#PED-1168 jsc#PED-1170 jsc#PED-1218 jsc#PED-1220 jsc#PED-1222 jsc#PED-1223 jsc#PED-1225
The documentation explicitly states we must prevent the output
2 and 3 from feeding from the same HVS channel.
Let's add a warning to make some noise if we ever find ourselves in such
a case.
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
Acked-by: Thomas Zimmermann <tzimmermann@suse.de>
Link: https://lore.kernel.org/r/20220328153659.2382206-6-maxime@cerno.tech
Acked-by: Patrik Jakobsson <pjakobsson@suse.de>
---
drivers/gpu/drm/vc4/vc4_kms.c | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/drivers/gpu/drm/vc4/vc4_kms.c b/drivers/gpu/drm/vc4/vc4_kms.c
index 0c6a5197d376..ffd54aab7759 100644
--- a/drivers/gpu/drm/vc4/vc4_kms.c
+++ b/drivers/gpu/drm/vc4/vc4_kms.c
@@ -290,6 +290,10 @@ static void vc5_hvs_pv_muxing_commit(struct vc4_dev *vc4,
switch (vc4_crtc->data->hvs_output) {
case 2:
+ drm_WARN_ON(&vc4->base,
+ VC4_GET_FIELD(HVS_READ(SCALER_DISPCTRL),
+ SCALER_DISPCTRL_DSP3_MUX) == channel);
+
mux = (channel == 2) ? 0 : 1;
reg = HVS_READ(SCALER_DISPECTRL);
HVS_WRITE(SCALER_DISPECTRL,
--
2.38.1