*** This bug is a duplicate of bug 1338706 ***
    https://bugs.launchpad.net/bugs/1338706

I have now sent a second email to Samsung's support, this time being
much more detailed about *exactly* why their drive is broken. If they
keep coming back with their retarded form-reply again, I will just keep
sending it, and will be talking to the two guys mentioned earlier who
have direct contacts at Samsung.

Here is the new email (to save time, I copied heavily from my previous
post here on this thread so readers will recognize lots of segments):

---
My Samsung 850 PRO 500gb drive came shipped with firmware EXM02B6Q from the 
factory.

This firmware revision includes SATA 3.2 spec features, but they are not
properly implemented.

The drive sets "ATA IDENTIFY's" word 77, bit 6 to 1 ("true"), which
means "RECEIVE/SEND FPDMA QUEUED supported".

But the firmware does NOT actually support RECV/SEND FPDMA QUEUED, and
just wrongly claims that it does. If you try to retrieve "log 13h" the
drive errors out, but the spec says that if RECV/SEND FPDMA is supported
then log 13h MUST also be supported.

So this is a case of Samsung's firmware department ticking a flag for
all the shiny SATA 3.2 features, and not actually making sure they
implemented them all.

A secondary problem of you incorrectly setting "ATA IDENTIFY's" word 77,
bit 6 to 1 ("true") is that FPDMA QUEUED TRIM *must* ALSO be supported
if you do that. But the drive does not support queued trim.

So the false advertisement of ATA IDENTIFY word 77 bit 6, without
actually supporting that new feature, means that the drive is severely
broken in multiple ways.

Two possible solutions to this situation:
1) A firmware update which sets "ATA IDENTIFY's" word 77, bit 6 to 0 ("FALSE!") 
instead, to PROPERLY show that the drive does NOT support SATA 3.2 FPDMA QUEUED 
features.
2) Alternatively, a firmware update which implements FPDMA QUEUED, log 13h, 
FPDMA QUEUED TRIM, etc, so that the drive actually supports what it *claims* it 
does.

Of these two, #1 is the easiest and makes the most sense. Either way,
there's a problem in the firmware and it needs a fix.

Thank you for your time,

Mark
---

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https://bugs.launchpad.net/bugs/1449005

Title:
  trim does not work with Samsung 840 EVO after firmware update
  (EXT0DB6Q)

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