synapticsmst: blacklist plugin when using amdgpu (Fixes: #1121)
synapticsmst: blacklist plugin when using amdgpu (Fixes: #1121)

An undiagnosed kernel issue is leading to a kernel crash involving
DP aux reads with amdgpu involved.

It's been reproduced in kernel 4.15 with a DKMS version of amdgpu as
well as kernel 4.19 with amdgpu within the kernel.

```
[16862.519947] [drm:generic_reg_wait [amdgpu]] *ERROR* REG_WAIT timeout 10us * 160 tries - submit_channel_request line:246
[16862.519983] WARNING: CPU: 5 PID: 3015 at drivers/gpu/drm/amd/amdgpu/../display/dc/dc_helper.c:254 generic_reg_wait+0xe2/0x160 [amdgpu]
[16862.519984] Modules linked in: rfcomm snd_hda_codec_realtek snd_hda_codec_generic cmac bnep arc4 nls_iso8859_1 amdkfd amd_iommu_v2 amdgpu i915 dell_rbtn iwlmvm snd_soc_skl wmi_bmof dell_wmi intel_rapl x86_pkg_temp_thermal dell_laptop intel_powerclamp snd_soc_skl_ipc dell_smbios coretemp snd_soc_sst_ipc dell_wmi_descriptor kvm_intel dcdbas snd_soc_sst_dsp snd_hda_ext_core kvmgt dell_smm_hwmon snd_soc_acpi_intel_match mac80211 vfio_mdev crct10dif_pclmul mdev vfio_iommu_type1 crc32_pclmul snd_soc_acpi vfio ghash_clmulni_intel snd_soc_core kvm pcbc snd_compress ac97_bus aesni_intel snd_hda_codec_hdmi snd_pcm_dmaengine chash gpu_sched aes_x86_64 snd_hda_intel crypto_simd snd_hda_codec cryptd ttm glue_helper pcmcia irqbypass snd_hda_core drm_kms_helper intel_cstate intel_rapl_perf snd_hwdep uvcvideo snd_pcm
[16862.520008]  drm cdc_ether iwlwifi cdc_mbim videobuf2_vmalloc snd_seq_midi videobuf2_memops cdc_ncm snd_seq_midi_event videobuf2_v4l2 snd_rawmidi videobuf2_common videodev input_leds serio_raw btusb qmi_wwan btrtl r8152 snd_seq btbcm media cdc_wdm btintel usbnet option mii usb_wwan bluetooth usbserial cdc_acm hid_multitouch joydev snd_seq_device snd_timer cfg80211 snd yenta_socket pcmcia_rsrc idma64 pcmcia_core soundcore virt_dma i2c_algo_bit fb_sys_fops syscopyarea mei_me sysfillrect ecdh_generic sysimgblt mei ucsi_acpi intel_lpss_pci processor_thermal_device typec_ucsi intel_lpss intel_soc_dts_iosf intel_pch_thermal typec wmi soc_button_array mac_hid intel_hid int3400_thermal video int3403_thermal dell_smo8800 sparse_keymap acpi_thermal_rel int340x_thermal_zone acpi_pad sch_fq_codel parport_pc
[16862.520033]  ppdev lp parport ip_tables x_tables autofs4 hid_generic usbhid uas usb_storage e1000e ahci libahci i2c_hid hid
[16862.520040] CPU: 5 PID: 3015 Comm: fwupd Not tainted 4.19.0 #1
[16862.520040] Hardware name: Dell Inc. Latitude 7424 Rugged Extreme/, BIOS 1.0.0 09/12/2018
[16862.520062] RIP: 0010:generic_reg_wait+0xe2/0x160 [amdgpu]
[16862.520063] Code: ab 44 8b 45 20 48 8b 4d 18 44 89 e6 8b 55 10 48 c7 c7 f0 bf 12 c1 44 89 4d d4 e8 79 1d 65 ff 41 83 7d 18 01 44 8b 4d d4 74 02 <0f> 0b 48 83 c4 18 44 89 c8 5b 41 5c 41 5d 41 5e 41 5f 5d c3 41 0f
[16862.520064] RSP: 0018:ffffbdff831ffbe0 EFLAGS: 00010297
[16862.520065] RAX: 0000000000000000 RBX: 00000000000000a1 RCX: 0000000000000000
[16862.520065] RDX: 0000000000000000 RSI: ffff965fee356428 RDI: ffff965fee356428
[16862.520066] RBP: ffffbdff831ffc20 R08: 00000000000004d5 R09: 00000000ffffffff
[16862.520066] R10: fffff464915dbd00 R11: ffffffff981923ed R12: 000000000000000a
[16862.520067] R13: ffff965fdea5d480 R14: 0000000000000001 R15: 0000000000000000
[16862.520068] FS:  00007f17444485c0(0000) GS:ffff965fee340000(0000) knlGS:0000000000000000
[16862.520068] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[16862.520069] CR2: 00007f1732987150 CR3: 000000045f4fe006 CR4: 00000000003606e0
[16862.520070] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[16862.520070] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[16862.520070] Call Trace:
[16862.520097]  submit_channel_request+0x394/0x480 [amdgpu]
[16862.520118]  dc_link_aux_transfer+0xca/0x160 [amdgpu]
[16862.520142]  dm_dp_aux_transfer+0x59/0x120 [amdgpu]
[16862.520146]  drm_dp_dpcd_access+0x75/0x110 [drm_kms_helper]
[16862.520148]  drm_dp_dpcd_read+0x33/0xc0 [drm_kms_helper]
[16862.520152]  auxdev_read_iter+0x10f/0x1d0 [drm_kms_helper]
[16862.520154]  __vfs_read+0x106/0x180
[16862.520155]  vfs_read+0x8e/0x130
[16862.520156]  ksys_read+0x55/0xc0
[16862.520157]  __x64_sys_read+0x1a/0x20
[16862.520159]  do_syscall_64+0x5a/0x120
[16862.520161]  entry_SYSCALL_64_after_hwframe+0x44/0xa9
[16862.520162] RIP: 0033:0x7f1741b3a384
[16862.520163] Code: 84 00 00 00 00 00 41 54 55 49 89 d4 53 48 89 f5 89 fb 48 83 ec 10 e8 8b fc ff ff 4c 89 e2 41 89 c0 48 89 ee 89 df 31 c0 0f 05 <48> 3d 00 f0 ff ff 77 38 44 89 c7 48 89 44 24 08 e8 c7 fc ff ff 48
[16862.520163] RSP: 002b:00007fffadd980f0 EFLAGS: 00000246 ORIG_RAX: 0000000000000000
[16862.520164] RAX: ffffffffffffffda RBX: 0000000000000013 RCX: 00007f1741b3a384
[16862.520165] RDX: 0000000000000001 RSI: 00007fffadd98154 RDI: 0000000000000013
[16862.520165] RBP: 00007fffadd98154 R08: 0000000000000000 R09: 000055fd7e9c7010
[16862.520166] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001
[16862.520166] R13: 00007fffadd981c0 R14: 00007fffadd98154 R15: 000055fd7eae35b0
[16862.520167] ---[ end trace 8e8b280a234718a5 ]---
[16862.520176] BUG: unable to handle kernel NULL pointer dereference at 0000000000000008
[16862.520177] PGD 0 P4D 0
[16862.520179] Oops: 0000 [#1] SMP PTI
[16862.520180] CPU: 5 PID: 3015 Comm: fwupd Tainted: G        W         4.19.0 #1
[16862.520181] Hardware name: Dell Inc. Latitude 7424 Rugged Extreme/, BIOS 1.0.0 09/12/2018
[16862.520205] RIP: 0010:dal_ddc_close+0xd/0x30 [amdgpu]
[16862.520207] Code: f1 00 e8 06 f5 ff ff 48 8b 55 f8 65 48 33 14 25 28 00 00 00 75 02 c9 c3 e8 70 09 65 d5 0f 1f 44 00 00 55 48 89 e5 53 48 89 fb <48> 8b 7f 08 e8 da f5 ff ff 48 8b 3b e8 d2 f5 ff ff 5b 5d c3 66 2e
[16862.520208] RSP: 0018:ffffbdff831ffc58 EFLAGS: 00010246
[16862.520209] RAX: ffffffffc103f410 RBX: 0000000000000000 RCX: 0000000000000000
[16862.520210] RDX: ffffffffc10de660 RSI: 0000000000005c58 RDI: 0000000000000000
[16862.520211] RBP: ffffbdff831ffc60 R08: 0000000000000001 R09: 00000000ffffffff
[16862.520211] R10: fffff464915dbd00 R11: 0000000000000001 R12: 0000000000000000
[16862.520212] R13: ffffbdff831ffdd0 R14: ffffbdff831ffd3d R15: 0000000000000000
[16862.520213] FS:  00007f17444485c0(0000) GS:ffff965fee340000(0000) knlGS:0000000000000000
[16862.520214] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[16862.520215] CR2: 0000000000000008 CR3: 000000045f4fe006 CR4: 00000000003606e0
[16862.520216] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[16862.520217] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[16862.520218] Call Trace:
[16862.520242]  release_engine+0x16/0x70 [amdgpu]
[16862.520263]  dc_link_aux_transfer+0xfd/0x160 [amdgpu]
[16862.520287]  dm_dp_aux_transfer+0x59/0x120 [amdgpu]
[16862.520290]  drm_dp_dpcd_access+0x75/0x110 [drm_kms_helper]
[16862.520293]  drm_dp_dpcd_read+0x33/0xc0 [drm_kms_helper]
[16862.520296]  auxdev_read_iter+0x10f/0x1d0 [drm_kms_helper]
[16862.520298]  __vfs_read+0x106/0x180
[16862.520300]  vfs_read+0x8e/0x130
[16862.520301]  ksys_read+0x55/0xc0
[16862.520302]  __x64_sys_read+0x1a/0x20
[16862.520304]  do_syscall_64+0x5a/0x120
[16862.520306]  entry_SYSCALL_64_after_hwframe+0x44/0xa9
[16862.520307] RIP: 0033:0x7f1741b3a384
[16862.520308] Code: 84 00 00 00 00 00 41 54 55 49 89 d4 53 48 89 f5 89 fb 48 83 ec 10 e8 8b fc ff ff 4c 89 e2 41 89 c0 48 89 ee 89 df 31 c0 0f 05 <48> 3d 00 f0 ff ff 77 38 44 89 c7 48 89 44 24 08 e8 c7 fc ff ff 48
[16862.520309] RSP: 002b:00007fffadd980f0 EFLAGS: 00000246 ORIG_RAX: 0000000000000000
[16862.520310] RAX: ffffffffffffffda RBX: 0000000000000013 RCX: 00007f1741b3a384
[16862.520311] RDX: 0000000000000001 RSI: 00007fffadd98154 RDI: 0000000000000013
[16862.520312] RBP: 00007fffadd98154 R08: 0000000000000000 R09: 000055fd7e9c7010
[16862.520312] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001
[16862.520313] R13: 00007fffadd981c0 R14: 00007fffadd98154 R15: 000055fd7eae35b0
[16862.520314] Modules linked in: rfcomm snd_hda_codec_realtek snd_hda_codec_generic cmac bnep arc4 nls_iso8859_1 amdkfd amd_iommu_v2 amdgpu i915 dell_rbtn iwlmvm snd_soc_skl wmi_bmof dell_wmi intel_rapl x86_pkg_temp_thermal dell_laptop intel_powerclamp snd_soc_skl_ipc dell_smbios coretemp snd_soc_sst_ipc dell_wmi_descriptor kvm_intel dcdbas snd_soc_sst_dsp snd_hda_ext_core kvmgt dell_smm_hwmon snd_soc_acpi_intel_match mac80211 vfio_mdev crct10dif_pclmul mdev vfio_iommu_type1 crc32_pclmul snd_soc_acpi vfio ghash_clmulni_intel snd_soc_core kvm pcbc snd_compress ac97_bus aesni_intel snd_hda_codec_hdmi snd_pcm_dmaengine chash gpu_sched aes_x86_64 snd_hda_intel crypto_simd snd_hda_codec cryptd ttm glue_helper pcmcia irqbypass snd_hda_core drm_kms_helper intel_cstate intel_rapl_perf snd_hwdep uvcvideo snd_pcm
[16862.520332]  drm cdc_ether iwlwifi cdc_mbim videobuf2_vmalloc snd_seq_midi videobuf2_memops cdc_ncm snd_seq_midi_event videobuf2_v4l2 snd_rawmidi videobuf2_common videodev input_leds serio_raw btusb qmi_wwan btrtl r8152 snd_seq btbcm media cdc_wdm btintel usbnet option mii usb_wwan bluetooth usbserial cdc_acm hid_multitouch joydev snd_seq_device snd_timer cfg80211 snd yenta_socket pcmcia_rsrc idma64 pcmcia_core soundcore virt_dma i2c_algo_bit fb_sys_fops syscopyarea mei_me sysfillrect ecdh_generic sysimgblt mei ucsi_acpi intel_lpss_pci processor_thermal_device typec_ucsi intel_lpss intel_soc_dts_iosf intel_pch_thermal typec wmi soc_button_array mac_hid intel_hid int3400_thermal video int3403_thermal dell_smo8800 sparse_keymap acpi_thermal_rel int340x_thermal_zone acpi_pad sch_fq_codel parport_pc
[16862.520351]  ppdev lp parport ip_tables x_tables autofs4 hid_generic usbhid uas usb_storage e1000e ahci libahci i2c_hid hid
[16862.520356] CR2: 0000000000000008
[16862.520357] ---[ end trace 8e8b280a234718a6 ]---
[16862.520380] RIP: 0010:dal_ddc_close+0xd/0x30 [amdgpu]
[16862.520382] Code: f1 00 e8 06 f5 ff ff 48 8b 55 f8 65 48 33 14 25 28 00 00 00 75 02 c9 c3 e8 70 09 65 d5 0f 1f 44 00 00 55 48 89 e5 53 48 89 fb <48> 8b 7f 08 e8 da f5 ff ff 48 8b 3b e8 d2 f5 ff ff 5b 5d c3 66 2e
[16862.520382] RSP: 0018:ffffbdff831ffc58 EFLAGS: 00010246
[16862.520384] RAX: ffffffffc103f410 RBX: 0000000000000000 RCX: 0000000000000000
[16862.520384] RDX: ffffffffc10de660 RSI: 0000000000005c58 RDI: 0000000000000000
[16862.520385] RBP: ffffbdff831ffc60 R08: 0000000000000001 R09: 00000000ffffffff
[16862.520386] R10: fffff464915dbd00 R11: 0000000000000001 R12: 0000000000000000
[16862.520387] R13: ffffbdff831ffdd0 R14: ffffbdff831ffd3d R15: 0000000000000000
[16862.520388] FS:  00007f17444485c0(0000) GS:ffff965fee340000(0000) knlGS:0000000000000000
[16862.520389] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[16862.520390] CR2: 0000000000000008 CR3: 000000045f4fe006 CR4: 00000000003606e0
[16862.520391] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[16862.520392] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
```

hughsie/fwupd,fwupd/fwupd,hughsie/fwupd,hughsie/fwupd,hughsie/fwupd,fwupd/fwupd,fwupd/fwupd,fwupd/fwupd