Commit fab823d8 authored by Vamsee Vardhan Thummala's avatar Vamsee Vardhan Thummala Committed by Thierry Reding
Browse files

gpu: host1x: Allow loading tegra-drm without enabled engines 



Add support to register host1x devices without requiring subdevices.
This ensures syncpoint functionality remains available even when engine
subdevices are not present.

Add softdep for tegra-drm to make userspace interface available
without module autoloading through device tree entries.

Signed-off-by: default avatarVamsee Vardhan Thummala <vthummala@nvidia.com>
[mperttunen@nvidia.com: some rewording]
Signed-off-by: default avatarMikko Perttunen <mperttunen@nvidia.com>
Signed-off-by: default avatarThierry Reding <treding@nvidia.com>
Link: https://lore.kernel.org/r/20250708-host1x-allow-no-subdevs-v1-1-93c66c251f03@nvidia.com
parent 63d47cc6

drivers/gpu/host1x/bus.c

+12 −0
Original line number Diff line number Diff line
@@ -471,6 +471,18 @@ static int host1x_device_add(struct host1x *host1x, 


	mutex_unlock(&clients_lock);



	/*

	 * Add device even if there are no subdevs to ensure syncpoint functionality

	 * is available regardless of whether any engine subdevices are present

	 */

	if (list_empty(&device->subdevs)) {

		err = device_add(&device->dev);

		if (err < 0)

			dev_err(&device->dev, "failed to add device: %d\n", err);

		else

			device->registered = true;

	}



	return 0;

}

drivers/gpu/host1x/dev.c

+1 −0
Original line number Diff line number Diff line
@@ -821,6 +821,7 @@ u64 host1x_get_dma_mask(struct host1x *host1x) 
}

EXPORT_SYMBOL(host1x_get_dma_mask);



MODULE_SOFTDEP("post: tegra-drm");

MODULE_AUTHOR("Thierry Reding <thierry.reding@avionic-design.de>");

MODULE_AUTHOR("Terje Bergstrom <tbergstrom@nvidia.com>");

MODULE_DESCRIPTION("Host1x driver for Tegra products");