drm/i915/bios: Tolerate devdata==NULL in intel_bios_encoder_supports_dp_dual_mode()

If we have no VBT, or the VBT didn't declare the encoder
in question, we won't have the 'devdata' for the encoder.
Instead of oopsing just bail early.

We won't be able to tell whether the port is DP++ or not,
but so be it.

Cc: stable@vger.kernel.org
Closes: https://gitlab.freedesktop.org/drm/intel/-/issues/10464
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240319092443.15769-1-ville.syrjala@linux.intel.com
Reviewed-by: Jani Nikula <jani.nikula@intel.com>
(cherry picked from commit 26410896206342c8a80d2b027923e9ee7d33b733)
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>

diff --git a/drivers/gpu/drm/i915/display/intel_bios.c b/drivers/gpu/drm/i915/display/intel_bios.c
index 9328601e4e9fa80f04240e8b87a63a4a765eb0de..52bd3576835b6ba15b31d8e17a94e9b65f612b1c 100644 (file)
--- a/drivers/gpu/drm/i915/display/intel_bios.c
+++ b/drivers/gpu/drm/i915/display/intel_bios.c
@@ -3382,6 +3382,9 @@ bool intel_bios_encoder_supports_dp_dual_mode(const struct intel_bios_encoder_da
 {
        const struct child_device_config *child = &devdata->child;
 
+       if (!devdata)
+               return false;
+
        if (!intel_bios_encoder_supports_dp(devdata) ||
            !intel_bios_encoder_supports_hdmi(devdata))
                return false;