resource_find_free_secondary_pipe_legacy() returns NULL when no free
pipe is available, but the result is only passed to ASSERT() (a
WARN_ON_ONCE() that does not stop execution) and then dereferenced in
split_stream_across_pipes() and dcn_bw_calc_rq_dlg_ttu().
The sibling resource callers (dcn10/dcn20/dcn201) already NULL-check
this function's result. Do the same here and skip the split when no
free pipe is available.
Found by Linux Verification Center (linuxtesting.org) with SVACE.
Fixes: 74c49c7ac14f ("drm/amdgpu/display: Add calcs code for DCN")
Signed-off-by: Dmitriy Chumachenko <Dmitry.Chumachenko@cyberprotect.ru>
---
drivers/gpu/drm/amd/display/dc/dml/calcs/dcn_calcs.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/drivers/gpu/drm/amd/display/dc/dml/calcs/dcn_calcs.c b/drivers/gpu/drm/amd/display/dc/dml/calcs/dcn_calcs.c
index 61553e24d53e..de54807ade43 100644
--- a/drivers/gpu/drm/amd/display/dc/dml/calcs/dcn_calcs.c
+++ b/drivers/gpu/drm/amd/display/dc/dml/calcs/dcn_calcs.c
@@ -1261,10 +1261,12 @@ bool dcn_validate_bandwidth(
/* pipe not split previously needs split */
hsplit_pipe = resource_find_free_secondary_pipe_legacy(&context->res_ctx, pool, pipe);
ASSERT(hsplit_pipe);
- split_stream_across_pipes(&context->res_ctx, pool, pipe, hsplit_pipe);
+ if (hsplit_pipe)
+ split_stream_across_pipes(&context->res_ctx, pool, pipe, hsplit_pipe);
}
- dcn_bw_calc_rq_dlg_ttu(dc, v, hsplit_pipe, input_idx);
+ if (hsplit_pipe)
+ dcn_bw_calc_rq_dlg_ttu(dc, v, hsplit_pipe, input_idx);
} else if (hsplit_pipe && hsplit_pipe->plane_state == pipe->plane_state) {
/* merge previously split pipe */
pipe->bottom_pipe = hsplit_pipe->bottom_pipe;
--
2.49.0