drm/amdgpu/display: use GFP_ATOMIC in dcn20_validate_bandwidth_internal

commit f41ed88 upstream.

GFP_KERNEL may and will sleep, and this is being executed in
a non-preemptible context; this will mess things up since it's
called inbetween DC_FP_START/END, and rescheduling will result
in the DC_FP_END later being called in a different context (or
just crashing if any floating point/vector registers/instructions
are used after the call is resumed in a different context).

Signed-off-by: Daniel Kolesa <daniel@octaforge.org>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/gpu/drm/amd/display/dc/dcn20/dcn20_resource.c

@@ -2845,7 +2845,7 @@ static bool dcn20_validate_bandwidth_internal(struct dc *dc, struct dc_state *co
 	int vlevel = 0;
 	int pipe_split_from[MAX_PIPES];
 	int pipe_cnt = 0;
-	display_e2e_pipe_params_st *pipes = kzalloc(dc->res_pool->pipe_count * sizeof(display_e2e_pipe_params_st), GFP_KERNEL);
+	display_e2e_pipe_params_st *pipes = kzalloc(dc->res_pool->pipe_count * sizeof(display_e2e_pipe_params_st), GFP_ATOMIC);
 	DC_LOGGER_INIT(dc->ctx->logger);
 
 	BW_VAL_TRACE_COUNT();