Description:
The last couple of months I have had this mildly annoying issue with Intel Fakeraid RAID0 with lvm.

During the first boot the following message is displayed in dmesg:
[code]
[ 3.147925] md126: detected capacity change from 0 to 3907039232
[ 3.149368] md126: p1 p2
[ 3.471734] random: lvm: uninitialized urandom read (4 bytes read)
[ 3.494218] device-mapper: uevent: version 1.0.3
[ 3.494439] device-mapper: ioctl: 4.45.0-ioctl (2021-03-22) initialised: dm-devel@redhat.com
[ 3.495224] device-mapper: table: 253:0: linear: Device lookup failed (-EBUSY)
[ 3.496607] device-mapper: ioctl: error adding target to table
[ 3.496635] random: lvm: uninitialized urandom read (2 bytes read)
[ 3.509931] device-mapper: table: 253:0: linear: Device lookup failed (-EBUSY)
[ 3.511302] device-mapper: ioctl: error adding target to table
[ 3.511341] random: lvm: uninitialized urandom read (2 bytes read)
[ 3.511780] device-mapper: table: 253:0: linear: Device lookup failed (-EBUSY)
[ 3.513164] device-mapper: ioctl: error adding target to table
[ 3.513958] device-mapper: table: 253:0: linear: Device lookup failed (-EBUSY)
[ 3.515342] device-mapper: ioctl: error adding target to table
[ 3.515789] device-mapper: table: 253:0: linear: Device lookup failed (-EBUSY)
[ 3.517179] device-mapper: ioctl: error adding target to table
[/code]

And the systems waits 10 seconds for the root device to appear and then drops to emergency shell. Rebooting with ctrl-alt-delete boots the system without problems.

Packages:
Mdadm version:
mdadm 4.2-2
LVM version:
lvm2 2.03.16-1
Kernel version:
5.17.9-arch1-1

Info:
mdadm --detail-platform
Platform : Intel(R) Rapid Storage Technology
Version : 9.5.0.1037
RAID Levels : raid0 raid1 raid10 raid5
Chunk Sizes : 4k 8k 16k 32k 64k 128k
2TB volumes : supported
2TB disks : not supported
Max Disks : 7
Max Volumes : 2 per array, 4 per controller
I/O Controller : /sys/devices/pci0000:00/0000:00:1f.2 (SATA)
Port3 : /dev/sdb (S1D9NSAF763538V)
Port2 : - non-disk device (hp BDDVDRW CH20L) -
Port1 : /dev/sda (S1D9NSAF761352V)
Port0 : - no device attached -
Port4 : - no device attached -
Port5 : - no device attached -

lsmod
Module Size Used by
ccm 20480 6
vboxnetflt 32768 0
vboxnetadp 28672 0
vboxdrv 544768 2 vboxnetadp,vboxnetflt
nvidia_uvm 2564096 0
nvidia_drm 69632 3
nvidia_modeset 1204224 5 nvidia_drm
rt2800pci 20480 0
rt2800mmio 20480 1 rt2800pci
rt2800lib 147456 2 rt2800mmio,rt2800pci
snd_hda_codec_realtek 167936 1
rt2x00pci 16384 1 rt2800pci
snd_hda_codec_generic 98304 1 snd_hda_codec_realtek
rt2x00mmio 16384 2 rt2800mmio,rt2800pci
ledtrig_audio 16384 1 snd_hda_codec_generic
rt2x00lib 98304 5 rt2x00mmio,rt2x00pci,rt2800mmio,rt2800pci,rt2800lib
snd_hda_codec_hdmi 81920 1
intel_powerclamp 20480 0
snd_hda_intel 61440 3
mac80211 1228800 3 rt2x00pci,rt2x00lib,rt2800lib
coretemp 20480 0
snd_intel_dspcfg 36864 1 snd_hda_intel
snd_intel_sdw_acpi 20480 1 snd_intel_dspcfg
iTCO_wdt 16384 0
kvm_intel 385024 0
libarc4 16384 1 mac80211
intel_pmc_bxt 16384 1 iTCO_wdt
snd_hda_codec 184320 4 snd_hda_codec_generic,snd_hda_codec_hdmi,snd_hda_intel,snd_hda_codec_realtek
mei_pxp 20480 0
mei_wdt 16384 0
at24 28672 0
gpio_ich 16384 0
iTCO_vendor_support 16384 1 iTCO_wdt
wmi_bmof 16384 0
snd_hda_core 114688 5 snd_hda_codec_generic,snd_hda_codec_hdmi,snd_hda_intel,snd_hda_codec,snd_hda_codec_realtek
kvm 1101824 1 kvm_intel
cfg80211 1077248 2 rt2x00lib,mac80211
snd_hwdep 16384 1 snd_hda_codec
irqbypass 16384 1 kvm
r8169 106496 0
snd_pcm 167936 4 snd_hda_codec_hdmi,snd_hda_intel,snd_hda_codec,snd_hda_core
realtek 36864 1
intel_cstate 20480 0
joydev 28672 0
mousedev 24576 0
mdio_devres 16384 1 r8169
snd_timer 49152 1 snd_pcm
intel_uncore 212992 0
i2c_i801 45056 0
eeprom_93cx6 16384 1 rt2800pci
snd 126976 14 snd_hda_codec_generic,snd_hda_codec_hdmi,snd_hwdep,snd_hda_intel,snd_hda_codec,snd_hda_codec_realtek,snd_timer,snd_pcm
i7core_edac 45056 0
i2c_smbus 20480 1 i2c_i801
rfkill 36864 5 rt2x00lib,cfg80211
libphy 167936 3 r8169,mdio_devres,realtek
soundcore 16384 1 snd
lpc_ich 28672 0
wmi 45056 1 wmi_bmof
mei_me 53248 2
mei 167936 5 mei_wdt,mei_pxp,mei_me
acpi_cpufreq 32768 1
mac_hid 16384 0
nvidia 35405824 220 nvidia_uvm,nvidia_modeset
dm_multipath 45056 0
sg 45056 0
crypto_user 24576 0
fuse 172032 3
bpf_preload 16384 0
ip_tables 36864 0
x_tables 57344 1 ip_tables
ext4 999424 5
crc32c_generic 16384 0
crc16 16384 1 ext4
mbcache 16384 1 ext4
jbd2 192512 1 ext4
dm_mod 184320 18 dm_multipath
raid0 28672 1
md_mod 204800 7 raid0
firewire_ohci 53248 0
uas 32768 0
sr_mod 28672 0
firewire_core 81920 1 firewire_ohci
crc32c_intel 24576 5
cdrom 81920 1 sr_mod
usb_storage 81920 1 uas
usbhid 73728 0
crc_itu_t 16384 1 firewire_core

mkinitcpio.conf hooks:
HOOKS=(base udev autodetect keyboard modconf block mdadm_udev lvm2 filesystems fsck shutdown)

mdadm.conf:
DEVICE partitions
ARRAY /dev/md/imsm0 metadata=imsm UUID=e2590fd5:90b34a7e:4aac81d4:bbe68aaf
ARRAY /dev/md/raid0_0 container=/dev/md/imsm0 member=0 UUID=a2e74bd5:f5efb8f2:b9dee648:b302cb97

Steps to reproduce:
1. Create RAID0 on Intel(R) Rapid Storage Technology
2. Create lvm on RAID0
3. Prepare and run mkinitcpio and reboot