The only started in 4.3 kernel (at least RC-5), 4.2.x does not have this problem. The kernel panic happens immediately after the SDHC card is inserted, reproducibility is 100%. If the system boots up with the card already inserted, it will crash as soon as sdhci_pci module is loaded. If the module is unloaded/blacklisted, obviously, nothing happens as the system does not see the MMC card reader. The machine is Lenovo thinkpad T-510 laptop with Intel Westmere CPU/3400 series chipset running 64-bit kernel 4.3.0. (somewhat) relevant kernel configuration bits: # CONFIG_CALGARY_IOMMU is not set CONFIG_IOMMU_HELPER=y CONFIG_VFIO_IOMMU_TYPE1=m CONFIG_IOMMU_API=y CONFIG_IOMMU_SUPPORT=y # Generic IOMMU Pagetable Support CONFIG_IOMMU_IOVA=y # CONFIG_AMD_IOMMU is not set CONFIG_INTEL_IOMMU=y CONFIG_INTEL_IOMMU_DEFAULT_ON=y CONFIG_INTEL_IOMMU_FLOPPY_WA=y # CONFIG_IOMMU_STRESS is not set CONFIG_KVM_INTEL=m CONFIG_PCI_MMCONFIG=y # Supported MMC/SDIO adapters CONFIG_MMC=m # CONFIG_MMC_DEBUG is not set # CONFIG_MMC_CLKGATE is not set # MMC/SD/SDIO Card Drivers CONFIG_MMC_BLOCK=m CONFIG_MMC_BLOCK_MINORS=8 CONFIG_MMC_BLOCK_BOUNCE=y CONFIG_MMC_TEST=m # MMC/SD/SDIO Host Controller Drivers CONFIG_MMC_SDHCI=m CONFIG_MMC_SDHCI_PCI=m CONFIG_MMC_RICOH_MMC=y CONFIG_MMC_SDHCI_ACPI=m Card reader device: 0d:00.0 SD Host controller: Ricoh Co Ltd MMC/SD Host Controller (rev 01) Subsystem: Lenovo MMC/SD Host Controller Flags: bus master, fast devsel, latency 0, IRQ 16 Memory at f2100000 (32-bit, non-prefetchable) [size=256] Capabilities: [50] MSI: Enable- Count=1/1 Maskable- 64bit+ Capabilities: [78] Power Management version 3 Capabilities: [80] Express Endpoint, MSI 00 Capabilities: [100] Virtual Channel Capabilities: [800] Advanced Error Reporting Kernel driver in use: sdhci-pci Kernel modules: sdhci_pci The panic report caught via netconsole: [22946.904308] ------------[ cut here ]------------ [22946.906564] kernel BUG at drivers/iommu/intel-iommu.c:3485! [22946.908801] invalid opcode: 0000 [#1] PREEMPT SMP [22946.911113] Modules linked in: netconsole dm_mod bnep cpufreq_powersave cpufreq_stats cpufreq_conservative cpufreq_userspace coretemp intel_powerclamp kvm_intel kvm crct10dif_pclmul crc32_pclmul jitterentropy_rng hmac sha256_ssse3 sha256_generic drbg snd_hda_codec_hdmi ansi_cprng gpio_ich iTCO_wdt iTCO_vendor_support aesni_intel arc4 aes_x86_64 nouveau mxm_wmi lrw gf128mul glue_helper ablk_helper iwldvm cryptd psmouse mac80211 uvcvideo serio_raw pcspkr nd_e820 videobuf2_vmalloc ttm evdev videobuf2_memops i2c_algo_bit mousedev btusb videobuf2_core btrtl drm_kms_helper v4l2_common mac_hid btbcm videodev btintel drm snd_hda_codec_conexant bluetooth snd_hda_codec_generic iwlwifi syscopyarea sysfillrect sysimgblt fb_sys_fops snd_hda_intel snd_hda_codec cfg80211 snd_hda_core snd_hwdep i2c_i801 thinkpad_acpi lpc_ich snd_pcm sg mfd_core nvram i2c_core snd_timer intel_ips rfkill hwmon snd mei_me soundcore intel_agp mei tpm_tis intel_gtt shpchp tpm agpgart battery rtc_cmos ac video thermal wmi acpi_cpufreq button processor tp_smapi(O) thinkpad_ec(O) autofs4 ext4 crc16 mbcache jbd2 btrfs xor hid_generic usbhid hid raid6_pq sr_mod cdrom sd_mod uas usb_storage firewire_ohci ahci libahci crc32c_intel libata atkbd sdhci_pci scsi_mod ehci_pci sdhci ehci_hcd e1000e firewire_core mmc_core crc_itu_t ptp usbcore usb_common pps_core [22946.929431] CPU: 3 PID: 0 Comm: swapper/3 Tainted: G O 4.3.0-westmere #1 [22946.932551] Hardware name: LENOVO 4313CTO/4313CTO, BIOS 6MET92WW (1.52 ) 09/26/2012 [22946.935701] task: ffff88023231a580 ti: ffff88023232c000 task.ti: ffff88023232c000 [22946.938878] RIP: 0010:[<ffffffff813cacd0>] [<ffffffff813cacd0>] intel_unmap+0x1d0/0x210 [22946.942117] RSP: 0018:ffff88023bd83da8 EFLAGS: 00010046 [22946.945341] RAX: 0000000000000000 RBX: ffff880231ea5580 RCX: 0000000000000002 [22946.948592] RDX: 0000000000000000 RSI: 00000000fffebda0 RDI: ffff880231e7d098 [22946.951855] RBP: ffff88023bd83de0 R08: 0000000000000000 R09: 0000000000000000 [22946.955131] R10: 00000000563f08fc R11: 000000001849050d R12: ffff880231e7d098 [22946.958423] R13: ffff8800bacbbc20 R14: 00000000fffebda0 R15: 0000000000000000 [22946.961723] FS: 0000000000000000(0000) GS:ffff88023bd80000(0000) knlGS:0000000000000000 [22946.965051] CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b [22946.968387] CR2: 00000000e4d9c0e0 CR3: 0000000001a0c000 CR4: 00000000000006e0 [22946.971760] Stack: [22946.975131] ffff8800bacbbc60 0000000000000000 ffff880231ea5580 ffff880231ea5580 [22946.978598] ffff8800bacbbc20 0000000000000010 0000000000000000 ffff88023bd83df0 [22946.982064] ffffffff813cad22 ffff88023bd83e48 ffffffffc01090c2 0000000000000282 [22946.985546] Call Trace: [22946.988984] <IRQ> [22946.989016] [<ffffffff813cad22>] intel_unmap_sg+0x12/0x20 [22946.995844] [<ffffffffc01090c2>] sdhci_finish_data+0x142/0x340 [sdhci] [22946.999296] [<ffffffffc0109f54>] sdhci_irq+0x484/0x9b5 [sdhci] [22947.002759] [<ffffffff81078dea>] ? notifier_call_chain+0x4a/0x70 [22947.006222] [<ffffffff810affa9>] handle_irq_event_percpu+0x39/0x1b0 [22947.009694] [<ffffffff810b0160>] handle_irq_event+0x40/0x60 [22947.013160] [<ffffffff810b2e82>] handle_fasteoi_irq+0xc2/0x180 [22947.016633] [<ffffffff810070aa>] handle_irq+0x1a/0x30 [22947.020095] [<ffffffff81563ed7>] do_IRQ+0x57/0xf0 [22947.023553] [<ffffffff81562001>] common_interrupt+0x81/0x81 [22947.026992] <EOI> [22947.027023] [<ffffffff8142736e>] ? cpuidle_enter_state+0x13e/0x2b0 [22947.033852] [<ffffffff81427363>] ? cpuidle_enter_state+0x133/0x2b0 [22947.037286] [<ffffffff81427517>] cpuidle_enter+0x17/0x20 [22947.040717] [<ffffffff81099382>] call_cpuidle+0x32/0x60 [22947.044131] [<ffffffff814274f3>] ? cpuidle_select+0x13/0x20 [22947.047554] [<ffffffff8109964e>] cpu_startup_entry+0x29e/0x360 [22947.050969] [<ffffffff8103539b>] start_secondary+0x15b/0x190 [22947.054379] Code: 01 44 29 f1 e8 12 c6 ff ff 4c 89 ee 4c 89 ff e8 b7 8d ff ff 4c 89 e7 e8 0f c7 ff ff 48 83 c4 10 5b 41 5c 41 5d 41 5e 41 5f 5d c3 <0f> 0b 49 8b 54 24 50 48 85 d2 74 29 4c 8b 45 d0 4c 89 f1 48 c7 [22947.058834] RIP [<ffffffff813cacd0>] intel_unmap+0x1d0/0x210 [22947.062568] RSP <ffff88023bd83da8> [22947.066285] ---[ end trace 12b22e7424e94db4 ]--- [22947.069999] Kernel panic - not syncing: Fatal exception in interrupt [22947.073803] Kernel Offset: disabled [22947.077240] ---[ end Kernel panic - not syncing: Fatal exception in interrupt -- Denis -- To unsubscribe from this list: send the line "unsubscribe linux-mmc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html