On Mon, Jan 11, 2021 at 09:53:56AM +0100, Christian König wrote:
Am 08.01.21 um 22:58 schrieb Jeremy Cline:
dcn20_resource_construct() includes a number of kzalloc(GFP_KERNEL) calls which can sleep, but kernel_fpu_begin() disables preemption and sleeping in this context is invalid.
The only places the FPU appears to be required is in the init_soc_bounding_box() function and when calculating the {min,max}_fill_clk_mhz. Narrow the scope to just these two parts to avoid sleeping while using the FPU.
Fixes: 7a8a3430be15 ("amdgpu: Wrap FPU dependent functions in dc20") Cc: Timothy Pearson tpearson@raptorengineering.com Signed-off-by: Jeremy Cline jcline@redhat.com
Good catch, but I would rather replace the kzalloc(GFP_KERNEL) with a kzalloc(GFP_ATOMIC) for now.
We have tons of problems with this DC_FP_START()/DC_FP_END() annotations and are even in the process of moving them out of the file because the compiles tend to clutter FP registers even outside of the annotated ranges on some architectures.
Out of curiosity, what's the plan? Soft-fp implementation for DC so you can keep the algorithms all unchanged, or redoing them as some fixed point with careful review and retesting everything? Something else? -Daniel
Regards, Christian.
drivers/gpu/drm/amd/display/dc/dcn20/dcn20_resource.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-)
diff --git a/drivers/gpu/drm/amd/display/dc/dcn20/dcn20_resource.c b/drivers/gpu/drm/amd/display/dc/dcn20/dcn20_resource.c index e04ecf0fc0db..a4fa5bf016c1 100644 --- a/drivers/gpu/drm/amd/display/dc/dcn20/dcn20_resource.c +++ b/drivers/gpu/drm/amd/display/dc/dcn20/dcn20_resource.c @@ -3622,6 +3622,7 @@ static bool init_soc_bounding_box(struct dc *dc, if (bb && ASICREV_IS_NAVI12_P(dc->ctx->asic_id.hw_internal_rev)) { int i;
DC_FP_START();@@ -3721,6 +3722,7 @@ static bool init_soc_bounding_box(struct dc *dc, dcn2_0_nv12_soc.clock_limits[i].dram_speed_mts = fixed16_to_double_to_cpu(bb->clock_limits[i].dram_speed_mts); }
DC_FP_END();@@ -3777,8 +3779,6 @@ static bool dcn20_resource_construct( enum dml_project dml_project_version = get_dml_project_version(ctx->asic_id.hw_internal_rev);
- DC_FP_START();
- ctx->dc_bios->regs = &bios_regs; pool->base.funcs = &dcn20_res_pool_funcs;
@@ -3959,8 +3959,10 @@ static bool dcn20_resource_construct( ranges.reader_wm_sets[i].wm_inst = i; ranges.reader_wm_sets[i].min_drain_clk_mhz = PP_SMU_WM_SET_RANGE_CLK_UNCONSTRAINED_MIN; ranges.reader_wm_sets[i].max_drain_clk_mhz = PP_SMU_WM_SET_RANGE_CLK_UNCONSTRAINED_MAX;
DC_FP_START(); ranges.reader_wm_sets[i].min_fill_clk_mhz = (i > 0) ? (loaded_bb->clock_limits[i - 1].dram_speed_mts / 16) + 1 : 0; ranges.reader_wm_sets[i].max_fill_clk_mhz = loaded_bb->clock_limits[i].dram_speed_mts / 16;DC_FP_END(); ranges.num_reader_wm_sets = i + 1; }@@ -4125,12 +4127,10 @@ static bool dcn20_resource_construct( pool->base.oem_device = NULL; }
- DC_FP_END(); return true; create_fail:
- DC_FP_END(); dcn20_resource_destruct(pool); return false;