Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
From:   Nicolas Boichat <drinkcat@chromium.org>
To:     Rob Herring <robh+dt@kernel.org>
Cc:     David Airlie <airlied@linux.ie>, Daniel Vetter <daniel@ffwll.ch>,
        Mark Rutland <mark.rutland@arm.com>,
        Matthias Brugger <matthias.bgg@gmail.com>,
        Tomeu Vizoso <tomeu.vizoso@collabora.com>,
        Steven Price <steven.price@arm.com>,
        Alyssa Rosenzweig <alyssa.rosenzweig@collabora.com>,
        Liam Girdwood <lgirdwood@gmail.com>,
        Mark Brown <broonie@kernel.org>,
        dri-devel@lists.freedesktop.org, devicetree@vger.kernel.org,
        linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
        linux-mediatek@lists.infradead.org, hsinyi@chromium.org
Subject: [PATCH v2 3/7] drm/panfrost: Improve error reporting in panfrost_gpu_power_on
Date:   Wed,  8 Jan 2020 13:23:33 +0800
Message-Id: <20200108052337.65916-4-drinkcat@chromium.org>
In-Reply-To: <20200108052337.65916-1-drinkcat@chromium.org>
References: <20200108052337.65916-1-drinkcat@chromium.org>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

It is useful to know which component cannot be powered on.

Signed-off-by: Nicolas Boichat <drinkcat@chromium.org>

---

Was useful when trying to probe bifrost GPU, to understand what
issue we are facing.
---
 drivers/gpu/drm/panfrost/panfrost_gpu.c | 15 ++++++++++-----
 1 file changed, 10 insertions(+), 5 deletions(-)

diff --git a/drivers/gpu/drm/panfrost/panfrost_gpu.c b/drivers/gpu/drm/panfrost/panfrost_gpu.c
index 8822ec13a0d619f..ba02bbfcf28c011 100644
--- a/drivers/gpu/drm/panfrost/panfrost_gpu.c
+++ b/drivers/gpu/drm/panfrost/panfrost_gpu.c
@@ -308,21 +308,26 @@ void panfrost_gpu_power_on(struct panfrost_device *pfdev)
 	gpu_write(pfdev, L2_PWRON_LO, pfdev->features.l2_present);
 	ret = readl_relaxed_poll_timeout(pfdev->iomem + L2_READY_LO,
 		val, val == pfdev->features.l2_present, 100, 1000);
+	if (ret)
+		dev_err(pfdev->dev, "error powering up gpu L2");
 
 	gpu_write(pfdev, STACK_PWRON_LO, pfdev->features.stack_present);
-	ret |= readl_relaxed_poll_timeout(pfdev->iomem + STACK_READY_LO,
+	ret = readl_relaxed_poll_timeout(pfdev->iomem + STACK_READY_LO,
 		val, val == pfdev->features.stack_present, 100, 1000);
+	if (ret)
+		dev_err(pfdev->dev, "error powering up gpu stack");
 
 	gpu_write(pfdev, SHADER_PWRON_LO, pfdev->features.shader_present);
-	ret |= readl_relaxed_poll_timeout(pfdev->iomem + SHADER_READY_LO,
+	ret = readl_relaxed_poll_timeout(pfdev->iomem + SHADER_READY_LO,
 		val, val == pfdev->features.shader_present, 100, 1000);
+	if (ret)
+		dev_err(pfdev->dev, "error powering up gpu shader");
 
 	gpu_write(pfdev, TILER_PWRON_LO, pfdev->features.tiler_present);
-	ret |= readl_relaxed_poll_timeout(pfdev->iomem + TILER_READY_LO,
+	ret = readl_relaxed_poll_timeout(pfdev->iomem + TILER_READY_LO,
 		val, val == pfdev->features.tiler_present, 100, 1000);
-
 	if (ret)
-		dev_err(pfdev->dev, "error powering up gpu");
+		dev_err(pfdev->dev, "error powering up gpu tiler");
 }
 
 void panfrost_gpu_power_off(struct panfrost_device *pfdev)
-- 
2.24.1.735.g03f4e72817-goog