[PATCH v2 2/5] drm/panthor: Call panthor_gpu_coherency_init() after PM resume()

[Steven Price]

On 01/04/2025 19:23, Boris Brezillon wrote:
> 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
> 
> Fixes: dd7db8d911a1 ("drm/panthor: Explicitly set the coherency mode")
> Signed-off-by: Boris Brezillon <boris.brezillon at collabora.com>
> Reviewed-by: Liviu Dudau <liviu.dudau at arm.com>

Reviewed-by: Steven Price <steven.price at arm.com>

> ---
>  drivers/gpu/drm/panthor/panthor_device.c | 8 ++++----
>  1 file changed, 4 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/gpu/drm/panthor/panthor_device.c b/drivers/gpu/drm/panthor/panthor_device.c
> index a9da1d1eeb70..c73c1608d6e6 100644
> --- 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;