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drm/i915/dsi: fix DSI DCS backlight port handling

PATCH Superseded Jani Nikula 1 participant 4 messages Aug 16, 2022 – Aug 24, 2022

Subsystems (4)
Stable branch DRM drivers Intel i915 Intel DRM display for xe and i915 drivers
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Jani Nikula

author
#0 lore raw

cover drm/i915/dsi: fix DSI DCS backlight port handling

Hopefully fix a null pointer dereference in DSI DCS backlight handling.

Jani Nikula (3):
drm/i915/dsi: filter invalid backlight and CABC ports drm/i915/dsi: fix dual-link DSI backlight and CABC ports for display

    11+

drm/i915/dsi: use VBT backlight and CABC port definitions directly

 drivers/gpu/drm/i915/display/icl_dsi.c             |  7 +++++--
 drivers/gpu/drm/i915/display/intel_bios.c          | 10 ++++++----
 drivers/gpu/drm/i915/display/intel_dsi.h           |  3 ---
 .../gpu/drm/i915/display/intel_dsi_dcs_backlight.c | 14 ++++++++------
 drivers/gpu/drm/i915/display/vlv_dsi.c             |  7 +++++--
 5 files changed, 24 insertions(+), 17 deletions(-)
Signature · 1 line
2.34.1
author
#1 lore raw

PATCH 1/3 drm/i915/dsi: filter invalid backlight and CABC ports

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 [email protected]
Signed-off-by Jani Nikula <[email protected]>
---
 drivers/gpu/drm/i915/display/icl_dsi.c | 7 +++++++
 drivers/gpu/drm/i915/display/vlv_dsi.c | 7 +++++++
 2 files changed, 14 insertions(+)
drivers/gpu/drm/i915/display/icl_dsi.c +7 -0
index 5dcfa7feffa9..885c74f60366 100644
@@ -2070,7 +2070,14 @@ 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) {
drivers/gpu/drm/i915/display/vlv_dsi.c +7 -0
index b9b1fed99874..35136d26e517 100644
@@ -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. */
Signature · 1 line
2.34.1
author
#2 lore raw

PATCH 2/3 drm/i915/dsi: fix dual-link DSI backlight and CABC ports for display 11+

In reply to Jani Nikula

The VBT dual-link DSI backlight and CABC still use ports A and C, both in Bspec and code, while display 11+ DSI only supports ports A and B. Assume port C actually means port B for display 11+ when parsing VBT.

Bspec: 20154

Closes https://gitlab.freedesktop.org/drm/intel/-/issues/6476
Cc [email protected]
Signed-off-by Jani Nikula <[email protected]>
---
 drivers/gpu/drm/i915/display/intel_bios.c | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)
drivers/gpu/drm/i915/display/intel_bios.c +6 -4
index 51dde5bfd956..198a2f4920cc 100644
@@ -1596,6 +1596,8 @@ static void parse_dsi_backlight_ports(struct drm_i915_private *i915,
 				      struct intel_panel *panel,
 				      enum port port)
 {
+	enum port port_bc = DISPLAY_VER(i915) >= 11 ? PORT_B : PORT_C;
+
 	if (!panel->vbt.dsi.config->dual_link || i915->vbt.version < 197) {
 		panel->vbt.dsi.bl_ports = BIT(port);
 		if (panel->vbt.dsi.config->cabc_supported)

@@ -1609,11 +1611,11 @@ static void parse_dsi_backlight_ports(struct drm_i915_private *i915,
 		panel->vbt.dsi.bl_ports = BIT(PORT_A);
 		break;
 	case DL_DCS_PORT_C:
-		panel->vbt.dsi.bl_ports = BIT(PORT_C);
+		panel->vbt.dsi.bl_ports = BIT(port_bc);
 		break;
 	default:
 	case DL_DCS_PORT_A_AND_C:
-		panel->vbt.dsi.bl_ports = BIT(PORT_A) | BIT(PORT_C);
+		panel->vbt.dsi.bl_ports = BIT(PORT_A) | BIT(port_bc);
 		break;
 	}
 

@@ -1625,12 +1627,12 @@ static void parse_dsi_backlight_ports(struct drm_i915_private *i915,
 		panel->vbt.dsi.cabc_ports = BIT(PORT_A);
 		break;
 	case DL_DCS_PORT_C:
-		panel->vbt.dsi.cabc_ports = BIT(PORT_C);
+		panel->vbt.dsi.cabc_ports = BIT(port_bc);
 		break;
 	default:
 	case DL_DCS_PORT_A_AND_C:
 		panel->vbt.dsi.cabc_ports =
-					BIT(PORT_A) | BIT(PORT_C);
+					BIT(PORT_A) | BIT(port_bc);
 		break;
 	}
 }
Signature · 1 line
2.34.1
author
#3 lore raw

PATCH 3/3 drm/i915/dsi: use VBT backlight and CABC port definitions directly

In reply to Jani Nikula

Drop the intermediate values stored in intel_dsi and use the VBT values directly, now that they're conveniently stored in panel->vbt.

Signed-off-by Jani Nikula <[email protected]>
---
 drivers/gpu/drm/i915/display/icl_dsi.c             |  4 ----
 drivers/gpu/drm/i915/display/intel_dsi.h           |  3 ---
 .../gpu/drm/i915/display/intel_dsi_dcs_backlight.c | 14 ++++++++------
 drivers/gpu/drm/i915/display/vlv_dsi.c             |  4 ----
 4 files changed, 8 insertions(+), 17 deletions(-)
drivers/gpu/drm/i915/display/icl_dsi.c +0 -4
index 885c74f60366..c089e392a041 100644
@@ -2073,13 +2073,9 @@ void icl_dsi_init(struct drm_i915_private *dev_priv)
 	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) {
 		struct intel_dsi_host *host;
drivers/gpu/drm/i915/display/intel_dsi.h +0 -3
index eafef0a87fea..ce80bd8be519 100644
@@ -89,9 +89,6 @@ struct intel_dsi {
 	u8 escape_clk_div;
 	u8 dual_link;
 
-	u16 dcs_backlight_ports;
-	u16 dcs_cabc_ports;
-
 	/* RGB or BGR */
 	bool bgr_enabled;
drivers/gpu/drm/i915/display/intel_dsi_dcs_backlight.c +8 -6
index 1bc7118c56a2..20e466d843ce 100644
@@ -53,7 +53,7 @@ static u32 dcs_get_backlight(struct intel_connector *connector, enum pipe unused
 	enum port port;
 	size_t len = panel->backlight.max > U8_MAX ? 2 : 1;
 
-	for_each_dsi_port(port, intel_dsi->dcs_backlight_ports) {
+	for_each_dsi_port(port, panel->vbt.dsi.bl_ports) {
 		dsi_device = intel_dsi->dsi_hosts[port]->device;
 		mipi_dsi_dcs_read(dsi_device, MIPI_DCS_GET_DISPLAY_BRIGHTNESS,
 				  &data, len);

@@ -80,7 +80,7 @@ static void dcs_set_backlight(const struct drm_connector_state *conn_state, u32
 		data[1] = level;
 	}
 
-	for_each_dsi_port(port, intel_dsi->dcs_backlight_ports) {
+	for_each_dsi_port(port, panel->vbt.dsi.bl_ports) {
 		dsi_device = intel_dsi->dsi_hosts[port]->device;
 		mode_flags = dsi_device->mode_flags;
 		dsi_device->mode_flags &= ~MIPI_DSI_MODE_LPM;

@@ -93,12 +93,13 @@ static void dcs_set_backlight(const struct drm_connector_state *conn_state, u32
 static void dcs_disable_backlight(const struct drm_connector_state *conn_state, u32 level)
 {
 	struct intel_dsi *intel_dsi = enc_to_intel_dsi(to_intel_encoder(conn_state->best_encoder));
+	struct intel_panel *panel = &to_intel_connector(conn_state->connector)->panel;
 	struct mipi_dsi_device *dsi_device;
 	enum port port;
 
 	dcs_set_backlight(conn_state, 0);
 
-	for_each_dsi_port(port, intel_dsi->dcs_cabc_ports) {
+	for_each_dsi_port(port, panel->vbt.dsi.cabc_ports) {
 		u8 cabc = POWER_SAVE_OFF;
 
 		dsi_device = intel_dsi->dsi_hosts[port]->device;

@@ -106,7 +107,7 @@ static void dcs_disable_backlight(const struct drm_connector_state *conn_state,
 				   &cabc, sizeof(cabc));
 	}
 
-	for_each_dsi_port(port, intel_dsi->dcs_backlight_ports) {
+	for_each_dsi_port(port, panel->vbt.dsi.bl_ports) {
 		u8 ctrl = 0;
 
 		dsi_device = intel_dsi->dsi_hosts[port]->device;

@@ -127,10 +128,11 @@ static void dcs_enable_backlight(const struct intel_crtc_state *crtc_state,
 				 const struct drm_connector_state *conn_state, u32 level)
 {
 	struct intel_dsi *intel_dsi = enc_to_intel_dsi(to_intel_encoder(conn_state->best_encoder));
+	struct intel_panel *panel = &to_intel_connector(conn_state->connector)->panel;
 	struct mipi_dsi_device *dsi_device;
 	enum port port;
 
-	for_each_dsi_port(port, intel_dsi->dcs_backlight_ports) {
+	for_each_dsi_port(port, panel->vbt.dsi.bl_ports) {
 		u8 ctrl = 0;
 
 		dsi_device = intel_dsi->dsi_hosts[port]->device;

@@ -146,7 +148,7 @@ static void dcs_enable_backlight(const struct intel_crtc_state *crtc_state,
 				   &ctrl, sizeof(ctrl));
 	}
 
-	for_each_dsi_port(port, intel_dsi->dcs_cabc_ports) {
+	for_each_dsi_port(port, panel->vbt.dsi.cabc_ports) {
 		u8 cabc = POWER_SAVE_MEDIUM;
 
 		dsi_device = intel_dsi->dsi_hosts[port]->device;
drivers/gpu/drm/i915/display/vlv_dsi.c +0 -4
index 35136d26e517..784ae52059d1 100644
@@ -1936,13 +1936,9 @@ void vlv_dsi_init(struct drm_i915_private *dev_priv)
 	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. */
 	for_each_dsi_port(port, intel_dsi->ports) {
 		struct intel_dsi_host *host;
Signature · 1 line
2.34.1