linux-kernel - [RFC] drm/msm/adreno: Balance pm

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Date:   Fri, 3 Feb 2023 10:12:45 -0800
From:   Bjorn Andersson <quic_bjorande@...cinc.com>
To:     Rob Clark <robdclark@...il.com>,
        Abhinav Kumar <quic_abhinavk@...cinc.com>,
        Dmitry Baryshkov <dmitry.baryshkov@...aro.org>,
        Akhil P Oommen <quic_akhilpo@...cinc.com>
CC:     Sean Paul <sean@...rly.run>, David Airlie <airlied@...il.com>,
        "Daniel Vetter" <daniel@...ll.ch>,
        Konrad Dybcio <konrad.dybcio@...ainline.org>,
        <linux-arm-msm@...r.kernel.org>, <dri-devel@...ts.freedesktop.org>,
        <freedreno@...ts.freedesktop.org>, <linux-kernel@...r.kernel.org>
Subject: [RFC] drm/msm/adreno: Balance pm_runtime enable

When any of the components in the mdss hierarchy fails to bind,
previously bound components are being unbound again.

One such case happens when the DP controller fails to find its bridge or
panel, where adreno_unbind() will be invoked without adreno_load_gpu()
being called to invoke pm_runtime_enable().

The result is that once everything is bound the pm_runtime_get_sync()
call find the power-domain to have a positive disable_depth, fails
with -EACCESS and prevents the GPU device to be powered up.

Move the pm_runtime_enable() to adreno_bind(), in order to balance it
with any calls to adreno_unbind().

Fixes: 4b18299b3365 ("drm/msm/adreno: Defer enabling runpm until hw_init()")
Signed-off-by: Bjorn Andersson <quic_bjorande@...cinc.com>
---
 drivers/gpu/drm/msm/adreno/adreno_device.c | 11 ++---------
 1 file changed, 2 insertions(+), 9 deletions(-)

diff --git a/drivers/gpu/drm/msm/adreno/adreno_device.c b/drivers/gpu/drm/msm/adreno/adreno_device.c
index 36f062c7582f..ca38b837dedb 100644
--- a/drivers/gpu/drm/msm/adreno/adreno_device.c
+++ b/drivers/gpu/drm/msm/adreno/adreno_device.c
@@ -432,15 +432,6 @@ struct msm_gpu *adreno_load_gpu(struct drm_device *dev)
 	if (ret)
 		return NULL;
 
-	/*
-	 * Now that we have firmware loaded, and are ready to begin
-	 * booting the gpu, go ahead and enable runpm:
-	 */
-	pm_runtime_enable(&pdev->dev);
-
-	/* Make sure pm runtime is active and reset any previous errors */
-	pm_runtime_set_active(&pdev->dev);
-
 	ret = pm_runtime_get_sync(&pdev->dev);
 	if (ret < 0) {
 		pm_runtime_put_sync(&pdev->dev);
@@ -548,6 +539,8 @@ static int adreno_bind(struct device *dev, struct device *master, void *data)
 		return PTR_ERR(gpu);
 	}
 
+	pm_runtime_enable(dev);
+
 	return 0;
 }
 
-- 
2.25.1