[PATCH 5.19 006/207] drm/i915/dsi: filter invalid backlight and CABC ports

[Greg Kroah-Hartman]

From: Jani Nikula <jani.nikula@xxxxxxxxx>

[ Upstream commit 607f41768a1ef9c7721866b00fbdeeea5359bc07 ]

Avoid using ports that aren't initialized in case the VBT backlight or
CABC ports have invalid values. This fixes a NULL pointer dereference of
intel_dsi->dsi_hosts[port] in such cases.

Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Jani Nikula <jani.nikula@xxxxxxxxx>
Reviewed-by: Stanislav Lisovskiy <stanislav.lisovskiy@xxxxxxxxx>
Link: https://patchwork.freedesktop.org/patch/msgid/b0f4f087866257d280eb97d6bcfcefd109cc5fa2.1660664162.git.jani.nikula@xxxxxxxxx
(cherry picked from commit f4a6c7a454a6e71c5ccf25af82694213a9784013)
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@xxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 drivers/gpu/drm/i915/display/icl_dsi.c | 7 +++++++
 drivers/gpu/drm/i915/display/vlv_dsi.c | 7 +++++++
 2 files changed, 14 insertions(+)

diff --git a/drivers/gpu/drm/i915/display/icl_dsi.c b/drivers/gpu/drm/i915/display/icl_dsi.c
index 5c46acb46516..f416499dad6f 100644
--- a/drivers/gpu/drm/i915/display/icl_dsi.c
+++ b/drivers/gpu/drm/i915/display/icl_dsi.c
@@ -2072,7 +2072,14 @@ void icl_dsi_init(struct drm_i915_private *dev_priv)
 	else
 		intel_dsi->ports = BIT(port);
 
+	if (drm_WARN_ON(&dev_priv->drm, intel_connector->panel.vbt.dsi.bl_ports & ~intel_dsi->ports))
+		intel_connector->panel.vbt.dsi.bl_ports &= intel_dsi->ports;
+
 	intel_dsi->dcs_backlight_ports = intel_connector->panel.vbt.dsi.bl_ports;
+
+	if (drm_WARN_ON(&dev_priv->drm, intel_connector->panel.vbt.dsi.cabc_ports & ~intel_dsi->ports))
+		intel_connector->panel.vbt.dsi.cabc_ports &= intel_dsi->ports;
+
 	intel_dsi->dcs_cabc_ports = intel_connector->panel.vbt.dsi.cabc_ports;
 
 	for_each_dsi_port(port, intel_dsi->ports) {
diff --git a/drivers/gpu/drm/i915/display/vlv_dsi.c b/drivers/gpu/drm/i915/display/vlv_dsi.c
index be8fd3c362df..02f75e95b2ec 100644
--- a/drivers/gpu/drm/i915/display/vlv_dsi.c
+++ b/drivers/gpu/drm/i915/display/vlv_dsi.c
@@ -1933,7 +1933,14 @@ void vlv_dsi_init(struct drm_i915_private *dev_priv)
 	else
 		intel_dsi->ports = BIT(port);
 
+	if (drm_WARN_ON(&dev_priv->drm, intel_connector->panel.vbt.dsi.bl_ports & ~intel_dsi->ports))
+		intel_connector->panel.vbt.dsi.bl_ports &= intel_dsi->ports;
+
 	intel_dsi->dcs_backlight_ports = intel_connector->panel.vbt.dsi.bl_ports;
+
+	if (drm_WARN_ON(&dev_priv->drm, intel_connector->panel.vbt.dsi.cabc_ports & ~intel_dsi->ports))
+		intel_connector->panel.vbt.dsi.cabc_ports &= intel_dsi->ports;
+
 	intel_dsi->dcs_cabc_ports = intel_connector->panel.vbt.dsi.cabc_ports;
 
 	/* Create a DSI host (and a device) for each port. */
-- 
2.35.1