drm/panthor: Call panthor_gpu_coherency_init() after PM resume()

When the device is coherent, panthor_gpu_coherency_init() will read
GPU_COHERENCY_FEATURES to make sure the GPU supports the ACE-Lite
coherency protocol, which will fail if the clocks/power-domains are
not enabled when the read is done. Move the
panthor_gpu_coherency_init() call after the device has been resumed
to prevent that.

Changes in v2:
- Add Liviu's R-b

Changes in v3:
- Add Steve's R-b

Fixes: dd7db8d911a1 ("drm/panthor: Explicitly set the coherency mode")
Reviewed-by: Liviu Dudau <liviu.dudau@arm.com>
Reviewed-by: Steven Price <steven.price@arm.com>
Link: https://lore.kernel.org/r/20250404080933.2912674-3-boris.brezillon@collabora.com
Signed-off-by: Boris Brezillon <boris.brezillon@collabora.com>

diff --git a/drivers/gpu/drm/panthor/panthor_device.c b/drivers/gpu/drm/panthor/panthor_device.c
index a9da1d1eeb7071fb4fb7484f34becd4f9c5901d9..c73c1608d6e68c1f083cca19674a2f069a0f8554 100644 (file)
--- a/drivers/gpu/drm/panthor/panthor_device.c
+++ b/drivers/gpu/drm/panthor/panthor_device.c
@@ -171,10 +171,6 @@ int panthor_device_init(struct panthor_device *ptdev)
        struct page *p;
        int ret;
 
-       ret = panthor_gpu_coherency_init(ptdev);
-       if (ret)
-               return ret;
-
        init_completion(&ptdev->unplug.done);
        ret = drmm_mutex_init(&ptdev->base, &ptdev->unplug.lock);
        if (ret)
@@ -247,6 +243,10 @@ int panthor_device_init(struct panthor_device *ptdev)
        if (ret)
                goto err_rpm_put;
 
+       ret = panthor_gpu_coherency_init(ptdev);
+       if (ret)
+               return ret;
+
        ret = panthor_mmu_init(ptdev);
        if (ret)
                goto err_unplug_gpu;