drm/amdgpu: Add default case in DVI mode validation

amdgpu_connector_dvi_mode_valid() assigns max_digital_pixel_clock_khz
based on connector_object_id using a switch statement that lacks a
default case.

In practice this code path should never be hit because the existing
cases already cover all digital connector types that this function is
used for. This is also legacy display code which is not used for new
hardware.

Add a default case returning MODE_BAD to make the switch exhaustive and
silence the static analyzer smatch error. The new branch is effectively
defensive and should never be reached during normal operation.

Fixes: 585b2f685c56 ("drm/amdgpu: Respect max pixel clock for HDMI and DVI-D (v2)")
Cc: Dan Carpenter <dan.carpenter@linaro.org>
Cc: Timur Kristóf <timur.kristof@gmail.com>
Cc: Alex Deucher <alexander.deucher@amd.com>
Cc: Christian König <christian.koenig@amd.com>
Signed-off-by: Srinivasan Shanmugam <srinivasan.shanmugam@amd.com>
Acked-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_connectors.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_connectors.c
index aabe9d58c3dce993c3eb27a3e0507c62f6d3d784..b04fa9fd90b798bb5b84409bd64e7bcfc695720a 100644 (file)
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_connectors.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_connectors.c
@@ -1231,6 +1231,8 @@ static enum drm_mode_status amdgpu_connector_dvi_mode_valid(struct drm_connector
                case CONNECTOR_OBJECT_ID_HDMI_TYPE_B:
                        max_digital_pixel_clock_khz = max_dvi_single_link_pixel_clock * 2;
                        break;
+               default:
+                       return MODE_BAD;
                }
 
                /* When the display EDID claims that it's an HDMI display,