diff options
| author | Nicholas Kazlauskas <nicholas.kazlauskas@amd.com> | 2021-12-17 22:18:59 +0300 |
|---|---|---|
| committer | Alex Deucher <alexander.deucher@amd.com> | 2021-12-29 00:51:24 +0300 |
| commit | 33bb63915fee190102cae7d6576bc51a0bc342b2 (patch) | |
| tree | 5c0587784248e7e67ec098f9a3f0f33d67f2cb30 | |
| parent | 33735c1c8d0223170d79dbe166976d9cd7339c7a (diff) | |
| download | linux-33bb63915fee190102cae7d6576bc51a0bc342b2.tar.xz | |
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>
| -rw-r--r-- | drivers/gpu/drm/amd/display/dc/core/dc_link.c | 5 |
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) |