From e0f65089cb9af37831aa50359d30dcd218b61acf Mon Sep 17 00:00:00 2001
From: Maxime Ripard <mripard@kernel.org>
Date: Fri, 21 Jun 2024 16:20:32 +0100
Subject: [PATCH] drm/vc4: hdmi: Warn if writing to an unknown HDMI register

The VC4 HDMI driver has a bunch of accessors to read from a register.
The read accessor was warning when accessing an unknown register, but
the write one was just returning silently.

Let's make sure we warn also when writing to an unknown register.

Signed-off-by: Maxime Ripard <mripard@kernel.org>
Reviewed-by: Maxime Ripard <mripard@kernel.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20240621152055.4180873-9-dave.stevenson@raspberrypi.com
Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.com>
---
 drivers/gpu/drm/vc4/vc4_hdmi_regs.h | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

--- a/drivers/gpu/drm/vc4/vc4_hdmi_regs.h
+++ b/drivers/gpu/drm/vc4/vc4_hdmi_regs.h
@@ -498,8 +498,11 @@ static inline void vc4_hdmi_write(struct
 
 	field = &variant->registers[reg];
 	base = __vc4_hdmi_get_field_base(hdmi, field->reg);
-	if (!base)
+	if (!base) {
+		dev_warn(&hdmi->pdev->dev,
+			 "Unknown register ID %u\n", reg);
 		return;
+	}
 
 	writel(value, base + field->offset);
 }
