Commit 7da55c27e76749b9 ("drm/amd/display: Remove incorrect FP context start") removes the FP context protection of dml2_create(), and it said "All the DC_FP_START/END should be used before call anything from DML2".

However, dml2_validate()/dml21_validate() are not protected from their callers, causing such errors:

do_fpu invoked from kernel context![#1]: CPU: 10 UID: 0 PID: 331 Comm: kworker/10:1H Not tainted 6.14.0-rc6+ #4 Workqueue: events_highpri dm_irq_work_func [amdgpu] pc ffff800003191eb0 ra ffff800003191e60 tp 9000000107a94000 sp 9000000107a975b0 a0 9000000140ce4910 a1 0000000000000000 a2 9000000140ce49b0 a3 9000000140ce49a8 a4 9000000140ce49a8 a5 0000000100000000 a6 0000000000000001 a7 9000000107a97660 t0 ffff800003790000 t1 9000000140ce5000 t2 0000000000000001 t3 0000000000000000 t4 0000000000000004 t5 0000000000000000 t6 0000000000000000 t7 0000000000000000 t8 0000000100000000 u0 ffff8000031a3b9c s9 9000000130bc0000 s0 9000000132400000 s1 9000000140ec0000 s2 9000000132400000 s3 9000000140ce0000 s4 90000000057f8b88 s5 9000000140ec0000 s6 9000000140ce4910 s7 0000000000000001 s8 9000000130d45010 ra: ffff800003191e60 dml21_map_dc_state_into_dml_display_cfg+0x40/0x1140 [amdgpu] ERA: ffff800003191eb0 dml21_map_dc_state_into_dml_display_cfg+0x90/0x1140 [amdgpu] CRMD: 000000b0 (PLV0 -IE -DA +PG DACF=CC DACM=CC -WE) PRMD: 00000004 (PPLV0 +PIE -PWE) EUEN: 00000000 (-FPE -SXE -ASXE -BTE) ECFG: 00071c1d (LIE=0,2-4,10-12 VS=7) ESTAT: 000f0000 [FPD] (IS= ECode=15 EsubCode=0) PRID: 0014d010 (Loongson-64bit, Loongson-3C6000/S) Process kworker/10:1H (pid: 331, threadinfo=000000007bf9ddb0, task=00000000cc4ab9f3) Stack : 0000000100000000 0000043800000780 0000000100000001 0000000100000001 0000000000000000 0000078000000000 0000000000000438 0000078000000000 0000000000000438 0000078000000000 0000000000000438 0000000100000000 0000000100000000 0000000100000000 0000000100000000 0000000100000000 0000000000000001 9000000140ec0000 9000000132400000 9000000132400000 ffff800003408000 ffff800003408000 9000000132400000 9000000140ce0000 9000000140ce0000 ffff800003193850 0000000000000001 9000000140ec0000 9000000132400000 9000000140ec0860 9000000140ec0738 0000000000000001 90000001405e8000 9000000130bc0000 9000000140ec02a8 ffff8000031b5db8 0000000000000000 0000043800000780 0000000000000003 ffff8000031b79cc ... Call Trace: [<ffff800003191eb0>] dml21_map_dc_state_into_dml_display_cfg+0x90/0x1140 [amdgpu] [<ffff80000319384c>] dml21_validate+0xcc/0x520 [amdgpu] [<ffff8000031b8948>] dc_validate_global_state+0x2e8/0x460 [amdgpu] [<ffff800002e94034>] create_validate_stream_for_sink+0x3d4/0x420 [amdgpu] [<ffff800002e940e4>] amdgpu_dm_connector_mode_valid+0x64/0x240 [amdgpu] [<900000000441d6b8>] drm_connector_mode_valid+0x38/0x80 [<900000000441d824>] __drm_helper_update_and_validate+0x124/0x3e0 [<900000000441ddc0>] drm_helper_probe_single_connector_modes+0x2e0/0x620 [<90000000044050dc>] drm_client_modeset_probe+0x23c/0x1780 [<9000000004420384>] __drm_fb_helper_initial_config_and_unlock+0x44/0x5a0 [<9000000004403acc>] drm_client_dev_hotplug+0xcc/0x140 [<ffff800002e9ab50>] handle_hpd_irq_helper+0x1b0/0x1e0 [amdgpu] [<90000000038f5da0>] process_one_work+0x160/0x300 [<90000000038f6718>] worker_thread+0x318/0x440 [<9000000003901b8c>] kthread+0x12c/0x220 [<90000000038b1484>] ret_from_kernel_thread+0x8/0xa4

Unfortunately, protecting dml2_validate()/dml21_validate() out of DML2 causes "sleeping function called from invalid context", so protect them with DC_FP_START() and DC_FP_END() inside.

Cc: stable@vger.kernel.org Signed-off-by: Huacai Chen chenhuacai@loongson.cn --- .../gpu/drm/amd/display/dc/dml2/dml21/dml21_wrapper.c | 9 +++++++-- drivers/gpu/drm/amd/display/dc/dml2/dml2_wrapper.c | 5 +++++ 2 files changed, 12 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/amd/display/dc/dml2/dml21/dml21_wrapper.c b/drivers/gpu/drm/amd/display/dc/dml2/dml21/dml21_wrapper.c index bbc798e039f5..d124c38fbfd3 100644 --- a/drivers/gpu/drm/amd/display/dc/dml2/dml21/dml21_wrapper.c +++ b/drivers/gpu/drm/amd/display/dc/dml2/dml21/dml21_wrapper.c @@ -273,11 +273,16 @@ bool dml21_validate(const struct dc *in_dc, struct dc_state *context, struct dml { bool out = false;

+ DC_FP_START(); + /* Use dml_validate_only for fast_validate path */ - if (fast_validate) { + if (fast_validate) out = dml21_check_mode_support(in_dc, context, dml_ctx); - } else + else out = dml21_mode_check_and_programming(in_dc, context, dml_ctx); + + DC_FP_END(); + return out; }

diff --git a/drivers/gpu/drm/amd/display/dc/dml2/dml2_wrapper.c b/drivers/gpu/drm/amd/display/dc/dml2/dml2_wrapper.c index fc551c63c9e8..9cd140df132a 100644 --- a/drivers/gpu/drm/amd/display/dc/dml2/dml2_wrapper.c +++ b/drivers/gpu/drm/amd/display/dc/dml2/dml2_wrapper.c @@ -732,11 +732,16 @@ bool dml2_validate(const struct dc *in_dc, struct dc_state *context, struct dml2 return out; }

+ DC_FP_START(); + /* Use dml_validate_only for fast_validate path */ if (fast_validate) out = dml2_validate_only(context); else out = dml2_validate_and_build_resource(in_dc, context); + + DC_FP_END(); + return out; }

On 2025-03-27 05:53, Huacai Chen wrote:

Commit 7da55c27e76749b9 ("drm/amd/display: Remove incorrect FP context start") removes the FP context protection of dml2_create(), and it said "All the DC_FP_START/END should be used before call anything from DML2".

However, dml21_copy() are not protected from their callers, causing such errors:

do_fpu invoked from kernel context![#1]: CPU: 0 UID: 0 PID: 240 Comm: kworker/0:5 Not tainted 6.14.0-rc6+ #1 Workqueue: events work_for_cpu_fn pc ffff80000318bd2c ra ffff80000315750c tp 9000000105910000 sp 9000000105913810 a0 0000000000000000 a1 0000000000000002 a2 900000013140d728 a3 900000013140d720 a4 0000000000000000 a5 9000000131592d98 a6 0000000000017ae8 a7 00000000001312d0 t0 9000000130751ff0 t1 ffff800003790000 t2 ffff800003790000 t3 9000000131592e28 t4 000000000004c6a8 t5 00000000001b7740 t6 0000000000023e38 t7 0000000000249f00 t8 0000000000000002 u0 0000000000000000 s9 900000012b010000 s0 9000000131400000 s1 9000000130751fd8 s2 ffff800003408000 s3 9000000130752c78 s4 9000000131592da8 s5 9000000131592120 s6 9000000130751ff0 s7 9000000131592e28 s8 9000000131400008 ra: ffff80000315750c dml2_top_soc15_initialize_instance+0x20c/0x300 [amdgpu] ERA: ffff80000318bd2c mcg_dcn4_build_min_clock_table+0x14c/0x600 [amdgpu] CRMD: 000000b0 (PLV0 -IE -DA +PG DACF=CC DACM=CC -WE) PRMD: 00000004 (PPLV0 +PIE -PWE) EUEN: 00000000 (-FPE -SXE -ASXE -BTE) ECFG: 00071c1d (LIE=0,2-4,10-12 VS=7) ESTAT: 000f0000 [FPD] (IS= ECode=15 EsubCode=0) PRID: 0014d010 (Loongson-64bit, Loongson-3C6000/S) Process kworker/0:5 (pid: 240, threadinfo=00000000f1700428, task=0000000020d2e962) Stack : 0000000000000000 0000000000000000 0000000000000000 9000000130751fd8 9000000131400000 ffff8000031574e0 9000000130751ff0 0000000000000000 9000000131592e28 0000000000000000 0000000000000000 0000000000000000 0000000000000000 0000000000000000 0000000000000000 0000000000000000 0000000000000000 0000000000000000 0000000000000000 0000000000000000 0000000000000000 0000000000000000 0000000000000000 f9175936df5d7fd2 900000012b00ff08 900000012b000000 ffff800003409000 ffff8000034a1780 90000001019634c0 900000012b000010 90000001307beeb8 90000001306b0000 0000000000000001 ffff8000031942b4 9000000130780000 90000001306c0000 9000000130780000 ffff8000031c276c 900000012b044bd0 ffff800003408000 ... Call Trace: [<ffff80000318bd2c>] mcg_dcn4_build_min_clock_table+0x14c/0x600 [amdgpu] [<ffff800003157508>] dml2_top_soc15_initialize_instance+0x208/0x300 [amdgpu] [<ffff8000031942b0>] dml21_create_copy+0x30/0x60 [amdgpu] [<ffff8000031c2768>] dc_state_create_copy+0x68/0xe0 [amdgpu] [<ffff800002e98ea0>] amdgpu_dm_init+0x8c0/0x2060 [amdgpu] [<ffff800002e9a658>] dm_hw_init+0x18/0x60 [amdgpu] [<ffff800002b0a738>] amdgpu_device_init+0x1938/0x27e0 [amdgpu] [<ffff800002b0ce80>] amdgpu_driver_load_kms+0x20/0xa0 [amdgpu] [<ffff800002b008f0>] amdgpu_pci_probe+0x1b0/0x580 [amdgpu] [<9000000003c7eae4>] local_pci_probe+0x44/0xc0 [<90000000032f2b18>] work_for_cpu_fn+0x18/0x40 [<90000000032f5da0>] process_one_work+0x160/0x300 [<90000000032f6718>] worker_thread+0x318/0x440 [<9000000003301b8c>] kthread+0x12c/0x220 [<90000000032b1484>] ret_from_kernel_thread+0x8/0xa4

Unfortunately, protecting dml21_copy() out of DML2 causes "sleeping function called from invalid context", so protect them with DC_FP_START() and DC_FP_END() inside.

Cc: stable@vger.kernel.org Signed-off-by: Huacai Chen chenhuacai@loongson.cn

---

drivers/gpu/drm/amd/display/dc/dml2/dml21/dml21_wrapper.c | 4 ++++ 1 file changed, 4 insertions(+)

diff --git a/drivers/gpu/drm/amd/display/dc/dml2/dml21/dml21_wrapper.c b/drivers/gpu/drm/amd/display/dc/dml2/dml21/dml21_wrapper.c index fb80ba9287b6..a6b8df1d96e8 100644 --- a/drivers/gpu/drm/amd/display/dc/dml2/dml21/dml21_wrapper.c +++ b/drivers/gpu/drm/amd/display/dc/dml2/dml21/dml21_wrapper.c @@ -412,8 +412,12 @@ void dml21_copy(struct dml2_context *dst_dml_ctx, dst_dml_ctx->v21.mode_programming.programming = dst_dml2_programming;

• DC_FP_START();
• /* need to initialize copied instance for internal references to be correct */ dml2_initialize_instance(&dst_dml_ctx->v21.dml_init);
• DC_FP_END(); }

bool dml21_create_copy(struct dml2_context **dst_dml_ctx,

Thanks, we're adding this series to our weekly testing, and will have it merged if there are no issues.