First, thanks to the MakeMKV community for the tooling and documentation around UHD-friendly drives.
This post documents a reproducible setup for stabilizing a BU40N drive in a USB enclosure based on the INIC-1618L bridge, specifically under Linux where UASP-related issues can cause disconnects during UHD reads.
Hardware / Software Stack
- Drive: BU40N (UHD-friendly, reflashed to firmware 1.03)
- Enclosure: INIC-1618L (USB 3.0, single micro-B port)
- OS: Arch Linux
- Kernel: 6.19
- MakeMKV: 1.18.3
Observed Failure Modes (Linux only)
All issues below were reproducible under Linux but not present in Windows 10:
- USB device reset/disconnect during reads of dual-layer UHD (66GB) media
- Intermittent mount failures / excessive spin-up retries
- Inconsistent readability across UHD discs (especially layer transitions)
- Excessive seek noise during TOC read / initial access
- Device disconnect when inserting media with MakeMKV already polling the drive
The INIC-1618L bridge advertises UASP support, but in practice:
- UASP command queueing conflicts with optical drive behavior
- Layer transitions (L0 → L1) introduce latency interpreted as timeouts
- This triggers USB resets at the bridge level (visible in dmesg)
Mitigation: usb-storage quirks (disable UASP + stabilize probing)
Force fallback to BOT (Bulk-Only Transport) and reduce aggressive probing:
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options usb-storage quirks=13fd:0840:mku
- 13fd:0840 → INIC-1618L VID:PID
- u → disables UASP (critical)
- m → reduces aggressive probing
- k → avoids HID report ID conflicts (bridge quirk)
- Identify device:
Example:
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lsusbCode: Select all
Bus 003 Device 005: ID 13fd:0840 Initio Corporation INIC-1618L SATA - Create quirk config:
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echo 'options usb-storage quirks=13fd:0840:mku' | sudo tee /etc/modprobe.d/usb-storage-quirks.conf - Include in initramfs:
Modify:
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sudo nano /etc/mkinitcpio.confCode: Select all
FILES=(/etc/modprobe.d/usb-storage-quirks.conf) - Rebuild initramfs:
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sudo mkinitcpio -P - Reboot
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cat /sys/module/usb_storage/parameters/quirks
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13fd:0840:mku
- Device binds to usb-storage (not uas)
- No UAS driver attachment occurs
Combine entries as comma-separated:
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options usb-storage quirks=174c:1153:u,13fd:0840:mku
- 174c
u → disables UASP on ASM1153 bridge (UGREEN adapter)
- Do not insert media while MakeMKV is open (avoid concurrent polling + spin-up)
- Allow kernel to fully enumerate and stabilize (~5 seconds) before launching MakeMKV
- Allow cooldown between long UHD reads (~30 minutes recommended)
- Keep discs clean to reduce read retries
If disconnects persist:
- Remove drive from enclosure
- Use a powered SATA → USB adapter
- Use a Slimline SATA adapter
What NOT to do
- Avoid USB hubs (even powered)
- They add latency and increase transport-level instability
- They can worsen UASP-related issues
The key fix is:
Disable UASP ("u" quirk) for INIC-1618L-based enclosures
Everything else is secondary tuning.