dcn21_validate_bandwidth_fp() is invoked while FPU access has been
enabled. FPU access requires disabling preemption even on PREEMPT_RT.
It is not possible to allocate memory with disabled preemption even with
GFP_ATOMIC on PREEMPT_RT.

Move the memory allocation before FPU access is enabled.

Link: https://bugzilla.kernel.org/show_bug.cgi?id=217928
Signed-off-by: Sebastian Andrzej Siewior <bige...@linutronix.de>
---
 drivers/gpu/drm/amd/display/dc/dcn21/dcn21_resource.c | 10 +++++++++-
 drivers/gpu/drm/amd/display/dc/dml/dcn20/dcn20_fpu.c  |  7 ++-----
 drivers/gpu/drm/amd/display/dc/dml/dcn20/dcn20_fpu.h  |  5 ++---
 3 files changed, 13 insertions(+), 9 deletions(-)

diff --git a/drivers/gpu/drm/amd/display/dc/dcn21/dcn21_resource.c 
b/drivers/gpu/drm/amd/display/dc/dcn21/dcn21_resource.c
index d1a25fe6c44fa..5674c3450fc36 100644
--- a/drivers/gpu/drm/amd/display/dc/dcn21/dcn21_resource.c
+++ b/drivers/gpu/drm/amd/display/dc/dcn21/dcn21_resource.c
@@ -953,9 +953,17 @@ static bool dcn21_validate_bandwidth(struct dc *dc, struct 
dc_state *context,
                bool fast_validate)
 {
        bool voltage_supported;
+       display_e2e_pipe_params_st *pipes;
+
+       pipes = kcalloc(dc->res_pool->pipe_count, 
sizeof(display_e2e_pipe_params_st), GFP_KERNEL);
+       if (!pipes)
+               return false;
+
        DC_FP_START();
-       voltage_supported = dcn21_validate_bandwidth_fp(dc, context, 
fast_validate);
+       voltage_supported = dcn21_validate_bandwidth_fp(dc, context, 
fast_validate, pipes);
        DC_FP_END();
+
+       kfree(pipes);
        return voltage_supported;
 }
 
diff --git a/drivers/gpu/drm/amd/display/dc/dml/dcn20/dcn20_fpu.c 
b/drivers/gpu/drm/amd/display/dc/dml/dcn20/dcn20_fpu.c
index 5805fb02af14e..8b2038162a7e1 100644
--- a/drivers/gpu/drm/amd/display/dc/dml/dcn20/dcn20_fpu.c
+++ b/drivers/gpu/drm/amd/display/dc/dml/dcn20/dcn20_fpu.c
@@ -2216,9 +2216,8 @@ static void dcn21_calculate_wm(struct dc *dc, struct 
dc_state *context,
                                                &context->bw_ctx.dml, pipes, 
pipe_cnt);
 }
 
-bool dcn21_validate_bandwidth_fp(struct dc *dc,
-                                struct dc_state *context,
-                                bool fast_validate)
+bool dcn21_validate_bandwidth_fp(struct dc *dc, struct dc_state *context,
+                                bool fast_validate, display_e2e_pipe_params_st 
*pipes)
 {
        bool out = false;
 
@@ -2227,7 +2226,6 @@ bool dcn21_validate_bandwidth_fp(struct dc *dc,
        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_ATOMIC);
        DC_LOGGER_INIT(dc->ctx->logger);
 
        BW_VAL_TRACE_COUNT();
@@ -2267,7 +2265,6 @@ bool dcn21_validate_bandwidth_fp(struct dc *dc,
        out = false;
 
 validate_out:
-       kfree(pipes);
 
        BW_VAL_TRACE_FINISH();
 
diff --git a/drivers/gpu/drm/amd/display/dc/dml/dcn20/dcn20_fpu.h 
b/drivers/gpu/drm/amd/display/dc/dml/dcn20/dcn20_fpu.h
index c51badf7b68a9..a81a0b9e68842 100644
--- a/drivers/gpu/drm/amd/display/dc/dml/dcn20/dcn20_fpu.h
+++ b/drivers/gpu/drm/amd/display/dc/dml/dcn20/dcn20_fpu.h
@@ -77,9 +77,8 @@ int dcn21_populate_dml_pipes_from_context(struct dc *dc,
                                          struct dc_state *context,
                                          display_e2e_pipe_params_st *pipes,
                                          bool fast_validate);
-bool dcn21_validate_bandwidth_fp(struct dc *dc,
-                                struct dc_state *context,
-                                bool fast_validate);
+bool dcn21_validate_bandwidth_fp(struct dc *dc, struct dc_state *context, bool
+                                fast_validate, display_e2e_pipe_params_st 
*pipes);
 void dcn21_update_bw_bounding_box(struct dc *dc, struct clk_bw_params 
*bw_params);
 
 void dcn21_clk_mgr_set_bw_params_wm_table(struct clk_bw_params *bw_params);
-- 
2.40.1

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