linux.git/drivers/nvme/host/core.c, branch v4.11

nvme: Quirk APST off on "THNSF5256GPUK TOSHIBA"

2017-04-20T20:42:10+00:00

There's a report that it malfunctions with APST on.

See https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1678184

Cc: Kai-Heng Feng 
Signed-off-by: Andy Lutomirski 
Signed-off-by: Jens Axboe

nvme: Adjust the Samsung APST quirk

2017-04-20T20:42:09+00:00

I got a couple more reports: the Samsung APST issues appears to
affect multiple 950-series devices in Dell XPS 15 9550 and Precision
5510 laptops.  Change the quirk: rather than blacklisting the
firmware on the first problematic SSD that was reported, disable
APST on all 144d:a802 devices if they're installed in the two
affected Dell models.  While we're at it, disable only the deepest
sleep state instead of all of them -- the reporters say that this is
sufficient to fix the problem.

(I have a device that appears to be entirely identical to one of the
affected devices, but I have a different Dell laptop, so it's not
the case that all Samsung devices with firmware BXW75D0Q are broken
under all circumstances.)

Samsung engineers have an affected system, and hopefully they'll
give us a better workaround some time soon.  In the mean time, this
should minimize regressions.

See https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1678184

Cc: Kai-Heng Feng 
Signed-off-by: Andy Lutomirski 
Signed-off-by: Jens Axboe

nvme: add missing byte swap in nvme_setup_discard

2017-04-02T07:24:15+00:00

Fixes: b35ba01e ("nvme: support ranged discard requests")
Signed-off-by: Christoph Hellwig 
Signed-off-by: Sagi Grimberg

nvme: Complete all stuck requests

2017-03-02T15:56:59+00:00

If the nvme driver is shutting down its controller, the drievr will not
start the queues up again, preventing blk-mq's hot CPU notifier from
making forward progress.

To fix that, this patch starts a request_queue freeze when the driver
resets a controller so no new requests may enter. The driver will wait
for frozen after IO queues are restarted to ensure the queue reference
can be reinitialized when nvme requests to unfreeze the queues.

If the driver is doing a safe shutdown, the driver will wait for the
controller to successfully complete all inflight requests so that we
don't unnecessarily fail them. Once the controller has been disabled,
the queues will be restarted to force remaining entered requests to end
in failure so that blk-mq's hot cpu notifier may progress.

Signed-off-by: Keith Busch 
Reviewed-by: Sagi Grimberg 
Signed-off-by: Jens Axboe

nvme/core: Fix race kicking freed request_queue

2017-02-22T20:34:00+00:00

If a namespace has already been marked dead, we don't want to kick the
request_queue again since we may have just freed it from another thread.

Signed-off-by: Keith Busch 
Reviewed-by: Johannes Thumshirn 
Reviewed-by: Christoph Hellwig 
Signed-off-by: Sagi Grimberg 
Signed-off-by: Jens Axboe

nvme: Enable autonomous power state transitions

2017-02-22T20:34:00+00:00

NVMe devices can advertise multiple power states.  These states can
be either "operational" (the device is fully functional but possibly
slow) or "non-operational" (the device is asleep until woken up).
Some devices can automatically enter a non-operational state when
idle for a specified amount of time and then automatically wake back
up when needed.

The hardware configuration is a table.  For each state, an entry in
the table indicates the next deeper non-operational state, if any,
to autonomously transition to and the idle time required before
transitioning.

This patch teaches the driver to program APST so that each successive
non-operational state will be entered after an idle time equal to 100%
of the total latency (entry plus exit) associated with that state.
The maximum acceptable latency is controlled using dev_pm_qos
(e.g. power/pm_qos_latency_tolerance_us in sysfs); non-operational
states with total latency greater than this value will not be used.
As a special case, setting the latency tolerance to 0 will disable
APST entirely.  On hardware without APST support, the sysfs file will
not be exposed.

The latency tolerance for newly-probed devices is set by the module
parameter nvme_core.default_ps_max_latency_us.

In theory, the device can expose "default" APST table, but this
doesn't seem to function correctly on my device (Samsung 950), nor
does it seem particularly useful.  There is also an optional
mechanism by which a configuration can be "saved" so it will be
automatically loaded on reset.  This can be configured from
userspace, but it doesn't seem useful to support in the driver.

On my laptop, enabling APST seems to save nearly 1W.

The hardware tables can be decoded in userspace with nvme-cli.
'nvme id-ctrl /dev/nvmeN' will show the power state table and
'nvme get-feature -f 0x0c -H /dev/nvme0' will show the current APST
configuration.

This feature is quirked off on a known-buggy Samsung device.

Signed-off-by: Andy Lutomirski 
Reviewed-by: Christoph Hellwig 
Signed-off-by: Sagi Grimberg 
Signed-off-by: Jens Axboe

nvme: Add a quirk mechanism that uses identify_ctrl

2017-02-22T20:34:00+00:00

Currently, all NVMe quirks are based on PCI IDs.  Add a mechanism to
define quirks based on identify_ctrl's vendor id, model number,
and/or firmware revision.

Reviewed-by: Christoph Hellwig 
Signed-off-by: Andy Lutomirski 
Signed-off-by: Sagi Grimberg 
Signed-off-by: Jens Axboe

nvme: Use CNS as 8-bit field and avoid endianness conversion

2017-02-22T20:34:00+00:00

This patch defines CNS field as 8-bit field and avoids cpu_to/from_le
conversions.
Also initialize nvme_command cns value explicitly to NVME_ID_CNS_NS
for readability (don't rely on the fact that NVME_ID_CNS_NS = 0).

Reviewed-by: Max Gurtovoy 
Signed-off-by: Parav Pandit 
Reviewed-by: Keith Busch 
Signed-off-by: Sagi Grimberg 
Signed-off-by: Jens Axboe

nvme: add semicolon in nvme_command setting

2017-02-22T20:34:00+00:00

Reviewed-by: Parav Pandit 
Signed-off-by: Max Gurtovoy 
Reviewed-by: Keith Busch 
Signed-off-by: Sagi Grimberg 
Signed-off-by: Jens Axboe

nvme: Make controller state visible via sysfs

2017-02-22T20:34:00+00:00

Easier for debugging and testing state machine
transitions.

Signed-off-by: Sagi Grimberg 
Reviewed-by: Johannes Thumshirn 
Reviewed-by: Christoph Hellwig 
Signed-off-by: Jens Axboe