[PATCH] Revert "ARM: bcm283x: Switch V3D over to using the PM driver instead of firmware."

From: Stefan Wahren <wahrenst@gmx.net>
To: Eric Anholt <eric@anholt.net>,
	Florian Fainelli <f.fainelli@gmail.com>,
	Ray Jui <rjui@broadcom.com>,
	Scott Branden <sbranden@broadcom.com>,
	Paul Kocialkowski <paul.kocialkowski@bootlin.com>,
	boris.brezillon@bootlin.com
Cc: bcm-kernel-feedback-list@broadcom.com,
	linux-arm-kernel@lists.infradead.org,
	dri-devel@lists.freedesktop.org, Stefan Wahren <wahrenst@gmx.net>,
	stable@vger.kernel.org
Subject: [PATCH] Revert "ARM: bcm283x: Switch V3D over to using the PM driver instead of firmware."
Date: Sun,  8 Sep 2019 17:44:53 +0200	[thread overview]
Message-ID: <1567957493-4567-1-git-send-email-wahrenst@gmx.net> (raw)

Since release of the new BCM2835 PM driver there has been several reports
of V3D probing issues. This is caused by timeouts during powering-up the
GRAFX PM domain:

  bcm2835-power: Timeout waiting for grafx power OK

I was able to reproduce this reliable on my Raspberry Pi 3B+ after setting
force_turbo=1 in the firmware configuration. Since there are no issues
using the firmware PM driver with the same setup, there must be an issue
in the BCM2835 PM driver.

Unfortunately there hasn't been much progress in identifying the root cause
since June (mostly in the lack of documentation), so i decided to switch
back until the issue in the BCM2835 PM driver is fixed.

Link: https://github.com/raspberrypi/linux/issues/3046
Fixes: e1dc2b2e1bef (" ARM: bcm283x: Switch V3D over to using the PM driver instead of firmware.")
Cc: stable@vger.kernel.org
Signed-off-by: Stefan Wahren <wahrenst@gmx.net>
---
 arch/arm/boot/dts/bcm2835-rpi.dtsi | 4 ++++
 arch/arm/boot/dts/bcm283x.dtsi     | 4 +---
 2 files changed, 5 insertions(+), 3 deletions(-)

diff --git a/arch/arm/boot/dts/bcm2835-rpi.dtsi b/arch/arm/boot/dts/bcm2835-rpi.dtsi
index 6c6a7f6..b909e3b 100644
--- a/arch/arm/boot/dts/bcm2835-rpi.dtsi
+++ b/arch/arm/boot/dts/bcm2835-rpi.dtsi
@@ -67,6 +67,10 @@
 	power-domains = <&power RPI_POWER_DOMAIN_USB>;
 };

+&v3d {
+	power-domains = <&power RPI_POWER_DOMAIN_V3D>;
+};
+
 &vec {
 	power-domains = <&power RPI_POWER_DOMAIN_VEC>;
 	status = "okay";
diff --git a/arch/arm/boot/dts/bcm283x.dtsi b/arch/arm/boot/dts/bcm283x.dtsi
index 2d191fc..b238567 100644
--- a/arch/arm/boot/dts/bcm283x.dtsi
+++ b/arch/arm/boot/dts/bcm283x.dtsi
@@ -3,7 +3,6 @@
 #include <dt-bindings/clock/bcm2835-aux.h>
 #include <dt-bindings/gpio/gpio.h>
 #include <dt-bindings/interrupt-controller/irq.h>
-#include <dt-bindings/soc/bcm2835-pm.h>

 /* firmware-provided startup stubs live here, where the secondary CPUs are
  * spinning.
@@ -121,7 +120,7 @@
 			#interrupt-cells = <2>;
 		};

-		pm: watchdog@7e100000 {
+		watchdog@7e100000 {
 			compatible = "brcm,bcm2835-pm", "brcm,bcm2835-pm-wdt";
 			#power-domain-cells = <1>;
 			#reset-cells = <1>;
@@ -641,7 +640,6 @@
 			compatible = "brcm,bcm2835-v3d";
 			reg = <0x7ec00000 0x1000>;
 			interrupts = <1 10>;
-			power-domains = <&pm BCM2835_POWER_DOMAIN_GRAFX_V3D>;
 		};

 		vc4: gpu {
--
2.7.4

