Bug 215333

Summary: UAS keeps resetting disks
Product: IO/Storage Reporter: Daniel B (d.bergloev)
Component: SCSIAssignee: linux-scsi (linux-scsi)
Status: NEW ---    
Severity: blocking    
Priority: P1    
Hardware: All   
OS: Linux   
Kernel Version: Any Subsystem:
Regression: No Bisected commit-id:
Attachments: UAS Log from boot

Description Daniel B 2021-12-15 13:07:44 UTC 
Created attachment 300031 [details]
UAS Log from boot

Hi. 

Not sure what the benefit of UAS should supposed to be, considering that is never works, besides breaking things. I have had issues with this using specific USB Disks with live installers in the past, and now I spent a whole day debugging boot issues on two servers, caused by UAS on a specific USB/Sata adapter. 

https://superuser.com/questions/1693125/boot-loop-with-certain-sata-to-usb-adaptors/1693143#1693143 

I have written in detail the issue in the above link along with other details from various testing that I have done. But in general here is the problem. 

I had two different types of USB3/Sata adapters. One from Hama that seamed to work and another from DeLock that would cause boot issues due to the fact that UAS kept resetting the disks. I found that adding a quirks to usb-storage module, would stop that adapter from being used by UAS and would make it work properly. I also found that the Hama adapter was already pre-disabled within the usb-storage module, which is why it worked out-of-box. But it also means that neither of the adapters works with UAS. So if nothing works with this, but rather just produces problems for people (There are a ton of these issues across the web), why not remove it altogether. There may be some benefits from UAS (When it works), but considering how much havoc it creates, is it worth it?