A question about UAS

[Aaron Dewes <aaron.dewes@web.de>]

Hello!

Sorry if this suggestion/question sounds stupid, I don't have experience
with the kernel code and this mailing list.

I'm a contributor to Umbrel (getumbrel.com), and we provide a software
that allows to run a bitcoin node easily, and we've run into many people
having UAS issues, and we were manually adding quirks in this case. Now
I'm wondering if it is possible to disable UAS for all devices in the
kernel cmdline. This is my first question, but I also have another
suggestion. We've developed the following bash script to check for UAS
issues and automatically add quirks:

------

get_uas_string () {
   UDEVADM_DATA=$(sudo -u umbrel udevadm test /block/${block_device} 2> /dev/null) # Umbrel is the  main user on umbrel, and udevadm doesn't report the vendor id if running as root, which this script is
   ID_VENDOR=$(echo "${UDEVADM_DATA}" | grep "ID_VENDOR_ID" | sed 's/ID_VENDOR_ID=//')
   ID_MODEL=$(echo "${UDEVADM_DATA}" | grep "ID_MODEL_ID" | sed 's/ID_MODEL_ID=//')
   echo "${ID_VENDOR}:${ID_MODEL}:u"
}

if [[ $(dmesg) == *"uas_eh_abort_handler"* ]]; then
   echo "External storage might have UAS issues"
   UAS_STRING=$(get_uas_string)
   if [[ $(cat /boot/cmdline.txt) == *"${UAS_STRING}"* ]]; then
     sed "s/usb-storage.quirks=/usb-storage.quirks=$(get_uas_string),/g" -i /boot/cmdline.txt
     echo "Rebooting"
     sudo reboot
   fi
fi

-----

I was wondering if a check like this could be added to the kernel, so
every time uas_eh_abort_handler gets logged, which AFAIK only happens if
UAS has issues, a counter could be increased, so that, if it happens to
often, UAS gets disabled for that drive.

Are there any reasons not do do this because false positives could
happen? If yes, please let me know.

Aaron