From cdbebb3a92aca7327c88c6dc6ef5d4cd470d49fc Mon Sep 17 00:00:00 2001
From: Maxime Ripard <maxime@cerno.tech>
Date: Thu, 23 Feb 2023 19:44:32 +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 <maxime@cerno.tech>
---
 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);
 }
