Unverified Commit 86bf8cfd authored by Thierry Reding's avatar Thierry Reding Committed by Robert Foss
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drm/tegra: Remove existing framebuffer only if we support display 



Tegra DRM doesn't support display on Tegra234 and later, so make sure
not to remove any existing framebuffers in that case.

v2: - add comments explaining how this situation can come about
    - clear DRIVER_MODESET and DRIVER_ATOMIC feature bits

Fixes: 6848c291 ("drm/aperture: Convert drivers to aperture interfaces")
Signed-off-by: default avatarThierry Reding <treding@nvidia.com>
Reviewed-by: default avatarThomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: default avatarJavier Martinez Canillas <javierm@redhat.com>
Signed-off-by: default avatarRobert Foss <rfoss@kernel.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20240223150333.1401582-1-thierry.reding@gmail.com
parent f79ee787

drivers/gpu/drm/tegra/drm.c

+20 −3
Original line number Diff line number Diff line
@@ -1242,9 +1242,26 @@ static int host1x_drm_probe(struct host1x_device *dev) 


	drm_mode_config_reset(drm);



	/*

	 * Only take over from a potential firmware framebuffer if any CRTCs

	 * have been registered. This must not be a fatal error because there

	 * are other accelerators that are exposed via this driver.

	 *

	 * Another case where this happens is on Tegra234 where the display

	 * hardware is no longer part of the host1x complex, so this driver

	 * will not expose any modesetting features.

	 */

	if (drm->mode_config.num_crtc > 0) {

		err = drm_aperture_remove_framebuffers(&tegra_drm_driver);

		if (err < 0)

			goto hub;

	} else {

		/*

		 * Indicate to userspace that this doesn't expose any display

		 * capabilities.

		 */

		drm->driver_features &= ~(DRIVER_MODESET | DRIVER_ATOMIC);

	}



	err = drm_dev_register(drm, 0);

	if (err < 0)