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authorNicholas Kazlauskas <nicholas.kazlauskas@amd.com>2021-12-17 14:18:59 -0500
committerAlex Deucher <alexander.deucher@amd.com>2021-12-28 16:51:24 -0500
commit33bb63915fee190102cae7d6576bc51a0bc342b2 (patch)
tree5c0587784248e7e67ec098f9a3f0f33d67f2cb30 /drivers
parent33735c1c8d0223170d79dbe166976d9cd7339c7a (diff)
drm/amd/display: Fix USB4 null pointer dereference in update_psp_stream_config
[Why] A porting error on a previous patch left the block of code that causes the crash from a NULL pointer dereference. More specifically, we try to access link_enc before it's assigned in the USB4 case in the following assignment: config.dio_output_idx = link_enc->transmitter - TRANSMITTER_UNIPHY_A; [How] That assignment occurs later depending on the ASIC version. It's only needed on DCN31 and only after link_enc is already assigned. Fixes: 986430446c917b ("drm/amd/display: fix a crash on USB4 over C20 PHY") Reviewed-by: Harry Wentland <harry.wentland@amd.com> Signed-off-by: Nicholas Kazlauskas <nicholas.kazlauskas@amd.com> Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Diffstat (limited to 'drivers')
-rw-r--r--drivers/gpu/drm/amd/display/dc/core/dc_link.c5
1 files changed, 1 insertions, 4 deletions
diff --git a/drivers/gpu/drm/amd/display/dc/core/dc_link.c b/drivers/gpu/drm/amd/display/dc/core/dc_link.c
index c8457babfdea..c0bdc23702c8 100644
--- a/drivers/gpu/drm/amd/display/dc/core/dc_link.c
+++ b/drivers/gpu/drm/amd/display/dc/core/dc_link.c
@@ -3945,12 +3945,9 @@ static void update_psp_stream_config(struct pipe_ctx *pipe_ctx, bool dpms_off)
config.dig_be = pipe_ctx->stream->link->link_enc_hw_inst;
#if defined(CONFIG_DRM_AMD_DC_DCN)
config.stream_enc_idx = pipe_ctx->stream_res.stream_enc->id - ENGINE_ID_DIGA;
-
+
if (pipe_ctx->stream->link->ep_type == DISPLAY_ENDPOINT_PHY ||
pipe_ctx->stream->link->ep_type == DISPLAY_ENDPOINT_USB4_DPIA) {
- link_enc = pipe_ctx->stream->link->link_enc;
- config.dio_output_type = pipe_ctx->stream->link->ep_type;
- config.dio_output_idx = link_enc->transmitter - TRANSMITTER_UNIPHY_A;
if (pipe_ctx->stream->link->ep_type == DISPLAY_ENDPOINT_PHY)
link_enc = pipe_ctx->stream->link->link_enc;
else if (pipe_ctx->stream->link->ep_type == DISPLAY_ENDPOINT_USB4_DPIA)