drm/tegra: Remove existing framebuffer only if we support display

[ Upstream commit 86bf8cfda6d2a6720fa2e6e676c98f0882c9d3d7 ]

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: 6848c291a5 ("drm/aperture: Convert drivers to aperture interfaces")
Signed-off-by: Thierry Reding <treding@nvidia.com>
Reviewed-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Signed-off-by: Robert Foss <rfoss@kernel.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20240223150333.1401582-1-thierry.reding@gmail.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Thierry Reding 2024-02-23 16:03:33 +01:00 committed by Greg Kroah-Hartman
parent 274bf3cca1
commit 8e8c66afe2
1 changed files with 20 additions and 3 deletions

View File

@ -1242,9 +1242,26 @@ static int host1x_drm_probe(struct host1x_device *dev)
drm_mode_config_reset(drm);
err = drm_aperture_remove_framebuffers(&tegra_drm_driver);
if (err < 0)
goto hub;
/*
* 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)