On 17-07-2026 09:17, Suraj Kandpal wrote:
With introduction of force_hdcp14 we can now for HDCP 1.4 by passing HDCP 2.2 authentication but In MST, _intel_hdcp_disable() and _intel_hdcp2_disable() can return early when there are still other streams active on the port (num_streams > 0), leaving the per-connector hdcp_encrypted / hdcp2_encrypted flag stale. If the same connector is later re-enabled with the other HDCP version (e.g. HDCP 1.4 via force_hdcp14 after a prior HDCP 2.2 session on that connector) the stale flag from the previous protocol survives. intel_hdcp_disable() then picks the wrong branch on the next disable causing the following splat. xe 0000:00:02.0: [drm] drm_WARN_ON(!(intel_de_read(display, ((((&(display)->info.__runtime_info)->ip.ver) >= 12) ? ((const i915_reg_t){ .reg = (((0x664B4) + (cpu_transcoder) * ((0x665B4) - (0x664B4)))) }) : ((const i915_reg_t){ .reg = ((((const u32 []){ 0x66800, 0x66500, 0x66600, 0x66700, 0x66A00, 0x66900 })[(port)]) + (0xB4)) }))) & ((u32)(((int)sizeof(struct {_Static_assert(!(__builtin_choose_expr((sizeof(int) == sizeof(*(8 ? ((void *)((long)((20) >= (sizeof(u32) * 8)) * 0l)) : (int *)8))), (20)= (sizeof(u32) * 8), false)), "const_true((20) >= BITS_PER_TYPE(u32))"" is true");})) + ((((1ULL))) << (20)))))) WARNING: drivers/gpu/drm/i915/display/intel_hdcp.c:1969 at _intel_hdcp2_disable+0x4bf/0x520 [xe], CPU#2: kms_content_pro/101318 Modules linked in: xe vfio_pci_core vfio_iommu_type1 vfio iommufd xt_multiport snd_hda_codec_intelhdmi snd_hda_codec_hdmi drm_gpuvm drm_gpusvm_helper drm_buddy gpu_sched drm_ttm_helper ttm drm_suballoc_helper drm_exec drm_display_helper cec rc_core drm_kunit_helpers kunit i2c_algo_bit xt_conntrack xt_MASQUERADE bridge stp llc nft_chain_nat nf_nat nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 xt_addrtype nft_compat x_tables nf_tables xfrm_user xfrm_algo overlay cpuid cmdlinepart spi_nor mei_gsc_proxy mtd intel_rapl_msr wmi_bmof intel_uncore_frequency intel_uncore_frequency_common x86_pkg_temp_thermal intel_powerclamp coretemp snd_intel_dspcfg aesni_intel snd_hda_codec gf128mul snd_hda_core snd_hwdep r8169 snd_pcm intel_cstate snd_timer i2c_i801 i2c_mux snd spi_intel_pci processor_thermal_device_pci realtek video e1000e spi_intel i2c_smbus soundcore phy_package processor_thermal_device processor_thermal_wt_hint mei_me platform_temperature_control processor_thermal_soc_slider idma64 mei processor_thermal_rfim processor_thermal_rapl intel_ish_ipc intel_rapl_common intel_ishtp thunderbolt processor_thermal_wt_req processor_thermal_power_floor intel_vpu processor_thermal_mbox igen6_edac wmi sunrpc kvm_intel binfmt_misc kvm irqbypass int3403_thermal int340x_thermal_zone intel_skl_int3472_tps68470 tps68470_regulator intel_pmc_core clk_tps68470 acpi_tad int3400_thermal intel_hid pmt_telemetry acpi_thermal_rel sparse_keymap pmt_discovery pinctrl_intel_platform pmt_class intel_pmc_ssram_telemetry intel_pmc_pwrm_telemetry intel_skl_int3472_discrete intel_skl_int3472_common acpi_pad intel_vsec nls_iso8859_1 dm_multipath msr fuse efi_pstore autofs4 [last unloaded: xe_live_test] CPU: 2 UID: 0 PID: 101318 Comm: kms_content_pro Kdump: loaded Tainted: G U L N 7.2.0-rc2-lgci-xe-xe-5389-67aa8ad5c4c59cd1a-debug+ #1 PREEMPT(lazy) Tainted: [U]=USER, [L]=SOFTLOCKUP, [N]=TEST Hardware name: Intel Corporation Panther Lake Client Platform/PTL-UH LP5 T3 RVP1, BIOS PTLPFWI1.R00.3514.D01.2512291130 12/29/2025 RIP: 0010:_intel_hdcp2_disable+0x4c9/0x520 [xe] Code: 85 ff 74 04 48 8b 7f 08 4c 8b 7f 50 4d 85 ff 74 23 e8 5b 80 df e0 48 89 c6 48 8d 3d b1 f7 ba ff 48 c7 c1 a0 27 6a a1 4c 89 fa <67> 48 0f b9 3a e9 c9 fc ff ff 4c 8b 3f eb d8 e8 33 45 4e e1 4c 89 RSP: 0018:ffffc900027bf738 EFLAGS: 00010246 RAX: ffffffffa16bd4f1 RBX: ffff8881a1e69000 RCX: ffffffffa16a27a0 RDX: ffff8881c7b1b190 RSI: ffffffffa16bd4f1 RDI: ffffffffa100de30 RBP: ffffc900027bf7b0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: ffff88844397a000 R13: ffff88844397a000 R14: ffff88817f7d2000 R15: ffff8881c7b1b190 FS: 0000774e9299dbc0(0000) GS:ffff8884eb36c000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000774e94bc7220 CR3: 00000002166c1002 CR4: 0000000108f72ef0 PKRU: 55555554 Call Trace: <TASK> ? intel_hdcp_update_value+0x7d/0x260 [xe] intel_hdcp_disable+0x118/0x130 [xe] intel_hdcp_update_pipe+0x175/0x1b0 [xe] ? intel_initial_watermarks+0x20/0x60 [xe] intel_ddi_update_pipe+0x44/0xb0 [xe] intel_pre_update_crtc+0x3bc/0x410 [xe] skl_commit_modeset_enables+0x1a7/0x890 [xe] ? icl_sagv_pre_plane_update+0x6c/0xf0 [xe] intel_atomic_commit_tail+0x114b/0x20a0 [xe] ? lock_release+0xd0/0x2a0 intel_atomic_commit+0x2ff/0x350 [xe] ? intel_atomic_commit+0x2ff/0x350 [xe] drm_atomic_commit+0xaf/0xf0 ? __pfx___drm_printfn_info+0x10/0x10 drm_mode_atomic_ioctl+0xcb5/0xf60 ? drm_mode_atomic_ioctl+0x8a8/0xf60 ? drm_mode_atomic_ioctl+0x604/0xf60 ? __pfx_drm_mode_atomic_ioctl+0x10/0x10 drm_ioctl_kernel+0xb3/0x120 drm_ioctl+0x2db/0x5a0 ? __pfx_drm_mode_atomic_ioctl+0x10/0x10 ? _raw_spin_unlock_irqrestore+0x51/0x80 ? __pm_runtime_resume+0x5b/0x90 ? xe_pm_runtime_get_ioctl+0x61/0x150 [xe] xe_drm_ioctl+0x64/0xb0 [xe] __x64_sys_ioctl+0xa5/0x100 x64_sys_call+0x1250/0x26e0 do_syscall_64+0x103/0x6d0 ? __task_pid_nr_ns+0xc0/0x290 ? trace_hardirqs_on_prepare+0xcb/0xf0 ? do_syscall_64+0x34/0x6d0 ? fred_entry_from_user+0x92/0x140 ? trace_hardirqs_on+0x22/0xe0 ? do_syscall_64+0xb8/0x6d0 fred_entry_from_user+0x92/0x140 asm_fred_entrypoint_user+0x41/ Ensure the two flags are mutually exclusive at every successful enable: after intel_hdcp_auth() succeeds. Signed-off-by: Suraj Kandpal <[email protected]>
Tested-by: Santhosh Reddy Guddati <[email protected]> Reviewed-by: Santhosh Reddy Guddati <[email protected]>
--- drivers/gpu/drm/i915/display/intel_hdcp.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/gpu/drm/i915/display/intel_hdcp.c b/drivers/gpu/drm/i915/display/intel_hdcp.c index 0a076d2ed70a..e56df337dc6d 100644 --- a/drivers/gpu/drm/i915/display/intel_hdcp.c +++ b/drivers/gpu/drm/i915/display/intel_hdcp.c @@ -1075,6 +1075,7 @@ static int intel_hdcp1_enable(struct intel_connector *connector) ret = intel_hdcp_auth(connector); if (!ret) { hdcp->hdcp_encrypted = true; + hdcp->hdcp2_encrypted = false; return 0; }@@ -2109,6 +2110,7 @@ static int _intel_hdcp2_enable(struct intel_atomic_state *state,hdcp->content_type);hdcp->hdcp2_encrypted = true;+ hdcp->hdcp_encrypted = false; return 0; }
