On Tue, Aug 16, 2022 at 06:37:21PM +0300, Jani Nikula wrote:

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: stable@vger.kernel.org Signed-off-by: Jani Nikula jani.nikula@intel.com

Reviewed-by: Stanislav Lisovskiy stanislav.lisovskiy@intel.com

---

drivers/gpu/drm/i915/display/intel_bios.c | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/drivers/gpu/drm/i915/display/intel_bios.c b/drivers/gpu/drm/i915/display/intel_bios.c index 51dde5bfd956..198a2f4920cc 100644 --- a/drivers/gpu/drm/i915/display/intel_bios.c +++ b/drivers/gpu/drm/i915/display/intel_bios.c @@ -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; }

}

2.34.1