Samsung 840 EVO

["Günter Waller" <g.wal@web.de>]

Dear Tejun,
the subject Samsung SSD is having performance issues with "old data"
which Samsung now addresses with a new firmware. As often is the case,
Linux users find it a bit more difficult to apply that fix. However, I
also have a Windows system, so it should be no big deal for me.

But there is also a big concern for Linux users which this FW version
seems to introduce. The link below points to a warning (backed by
others, elsewhere on the web) that fstrim in combination with this FW
will wreck your drive.
http://www.overclock.net/t/1507897/samsung-840-evo-read-speed-drops-on-old-written-data-in-the-drive/2640%23post_23827674
(search for fstrim)
I raised this in a discussion thread of the Ubuntu MATE community and
was pointed to the SSD blacklist that is part of the module
libata-core.c which names you as the maintainer. I wonder if you could
take a look at this issue - maybe you want to add the device to the
blacklist thereafter if need be.
If you find the time and find this worthwhile to investigate I would
appreciate a brief notification of the outcome. For now I am holding
back the FW update.

Best regards

Guenter Waller