From: Nicolin Chen Date: Tue, 19 May 2020 09:03:01 +0000 (-0700) Subject: drm/tegra: hub: Do not enable orphaned window group X-Git-Tag: v5.15~3115^2~15^2~19 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=ef4e417eb3ec7fe657928f10ac1d2154d8a5fb38;p=platform%2Fkernel%2Flinux-starfive.git drm/tegra: hub: Do not enable orphaned window group 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 Signed-off-by: Thierry Reding --- diff --git a/drivers/gpu/drm/tegra/hub.c b/drivers/gpu/drm/tegra/hub.c index 8183e61..a2ef8f2 100644 --- a/drivers/gpu/drm/tegra/hub.c +++ b/drivers/gpu/drm/tegra/hub.c @@ -149,7 +149,9 @@ 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]; - tegra_windowgroup_enable(wgrp); + /* Skip orphaned window group whose parent DC is disabled */ + if (wgrp->parent) + tegra_windowgroup_enable(wgrp); } return 0; @@ -166,7 +168,9 @@ 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]; - tegra_windowgroup_disable(wgrp); + /* Skip orphaned window group whose parent DC is disabled */ + if (wgrp->parent) + tegra_windowgroup_disable(wgrp); } }