[devel] [PATCH 20/35] drm/panfrost: disable devfreq on Baikal-M

[asheplyakov на yandex.ru]

From: Alexey Sheplyakov <asheplyakov на altlinux.org>

Enabling GPU frequency scaling on Baikal-M cases GPU MMU lockup:

  [   38.108633] panfrost 2a200000.gpu: AS_ACTIVE bit stuck

Since GPU and CPU share the memory this locks up the whole system.
Therefore disable devfreq on Baikal-M.

X-DONTUPSTREAM
X-feature-Baikal-M
---
 drivers/gpu/drm/panfrost/panfrost_devfreq.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/gpu/drm/panfrost/panfrost_devfreq.c b/drivers/gpu/drm/panfrost/panfrost_devfreq.c
index 194af7f607a6..fc0e586f8f33 100644
--- a/drivers/gpu/drm/panfrost/panfrost_devfreq.c
+++ b/drivers/gpu/drm/panfrost/panfrost_devfreq.c
@@ -100,6 +100,10 @@ int panfrost_devfreq_init(struct panfrost_device *pfdev)
 		DRM_DEV_INFO(dev, "More than 1 supply is not supported yet\n");
 		return 0;
 	}
+	if (of_device_is_compatible(of_root, "baikal,baikal-m")) {
+		dev_info(pfdev->dev, "disabling GPU devfreq on BE-M1000\n");
+		return 0;
+	}
 
 	ret = devm_pm_opp_set_regulators(dev, pfdev->comp->supply_names,
 					 pfdev->comp->num_supplies);
-- 
2.32.0