Commit 9371b711 authored May 19, 2020 by Nicolin Chen Committed by Greg Kroah-Hartman Jul 16, 2020

drm/tegra: hub: Do not enable orphaned window group



[ Upstream commit ef4e417eb3ec7fe657928f10ac1d2154d8a5fb38 ]

Though the unconditional enable/disable code is not a final solution,
we don't want to run into a NULL pointer situation when window group
doesn't link to its DC parent if the DC is disabled in Device Tree.

So this patch simply adds a check to make sure that window group has
a valid parent before running into tegra_windowgroup_enable/disable.

Signed-off-by: Nicolin Chen <nicoleotsuka@gmail.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

parent 2c8af319

drivers/gpu/drm/tegra/hub.c

+6 −2

Original line number	Diff line number	Diff line
		@@ -143,6 +143,8 @@ int tegra_display_hub_prepare(struct tegra_display_hub *hub)
		for (i = 0; i < hub->soc->num_wgrps; i++) {
		struct tegra_windowgroup *wgrp = &hub->wgrps[i];

		/* Skip orphaned window group whose parent DC is disabled */
		if (wgrp->parent)
		tegra_windowgroup_enable(wgrp);
		}

		@@ -160,6 +162,8 @@ void tegra_display_hub_cleanup(struct tegra_display_hub *hub)
		for (i = 0; i < hub->soc->num_wgrps; i++) {
		struct tegra_windowgroup *wgrp = &hub->wgrps[i];

		/* Skip orphaned window group whose parent DC is disabled */
		if (wgrp->parent)
		tegra_windowgroup_disable(wgrp);
		}
		}