snd_bcm2835: disable HDMI audio when vc4 is used (#3640)

Things don't work too well when both the vc4 driver and the firmware driver are trying to control the same audio output: [ 763.569406] bcm2835_audio bcm2835_audio: vchi message timeout, msg=5 Hence, when the vc4 HDMI driver is used, let it control audio. This is done by introducing a new device tree property to the audio node, and extending the vc4-kms-v3d overlays to set it appropriately. Signed-off-by: Hristo Venev <[email protected]>
raspberrypi · Jun 10, 2020 · 46b071e · 46b071e
1 parent 0654fb6
commit 46b071e
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Showing 4 changed files with 22 additions and 2 deletions.
diff --git a/arch/arm/boot/dts/overlays/README b/arch/arm/boot/dts/overlays/README
@@ -2745,6 +2745,7 @@ Params: cma-256                 CMA is 256MB (needs 1GB)
         cma-size                CMA size in bytes, 4MB aligned
         cma-default             Use upstream's default value
         audio                   Enable or disable audio over HDMI (default "on")
+        noaudio                 Disable all HDMI audio (default "off")
 
 
 Name:   vc4-kms-v3d-pi4
@@ -2761,6 +2762,7 @@ Params: cma-256                 CMA is 256MB
                                 "on")
         audio1                  Enable or disable audio over HDMI1 (default
                                 "on")
+        noaudio                 Disable all HDMI audio (default "off")
 
 
 Name:   vga666

diff --git a/arch/arm/boot/dts/overlays/vc4-kms-v3d-overlay.dts b/arch/arm/boot/dts/overlays/vc4-kms-v3d-overlay.dts
@@ -108,7 +108,15 @@
 		};
 	};
 
+	fragment@14 {
+		target = <&audio>;
+		__overlay__  {
+		    brcm,disable-hdmi;
+		};
+	};
+
 	__overrides__ {
-		audio   = <0>,"!13";
+		audio   = <0>,"!13", <0>,"=14";
+		noaudio = <0>,"=13", <0>,"!14";
 	};
 };
diff --git a/arch/arm/boot/dts/overlays/vc4-kms-v3d-pi4-overlay.dts b/arch/arm/boot/dts/overlays/vc4-kms-v3d-pi4-overlay.dts
@@ -138,8 +138,16 @@
 		};
 	};
 
+	fragment@19 {
+		target = <&audio>;
+		__overlay__  {
+		    brcm,disable-hdmi;
+		};
+	};
+
 	__overrides__ {
 		audio   = <0>,"!17";
 		audio1   = <0>,"!18";
+		noaudio = <0>,"=17", <0>,"=18", <0>,"!19";
 	};
 };
diff --git a/drivers/staging/vc04_services/bcm2835-audio/bcm2835.c b/drivers/staging/vc04_services/bcm2835-audio/bcm2835.c
@@ -381,7 +381,9 @@ static int snd_bcm2835_alsa_probe(struct platform_device *pdev)
 	}
 
 	if (!enable_compat_alsa) {
-		set_hdmi_enables(dev);
+		if (!of_property_read_bool(dev->of_node, "brcm,disable-hdmi"))
+			set_hdmi_enables(dev);
+
 		// In this mode, always enable analog output
 		enable_headphones = true;
 	} else {