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

PATCH Applied Nicolin Chen 2 participants 2 messages May 19, 2020 – May 22, 2020

Subsystems (3)
DRM drivers Tegra architecture support DRM drivers for NVIDIA Tegra
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Nicolin Chen

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#0 lore raw

PATCH 1/1 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 <[email protected]>
---
 drivers/gpu/drm/tegra/hub.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)
drivers/gpu/drm/tegra/hub.c +6 -2
index 8183e617bf6b..a2ef8f218d4e 100644
@@ -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);
 	}
 }
Signature · 1 line
2.17.1
Applied
#1 lore raw
Quoted 11 lines · Nicolin Chen

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 <[email protected]>
---
 drivers/gpu/drm/tegra/hub.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

Applied, thanks.

Thierry