During the hardware start sequence, do not overwrite the driver state
and do not proceed with the initialization sequence if the state
was changed while the driver was waiting for the start interrupt.

This can happen if the driver's removal/stop procedure was triggered
from the parent level while the driver is waiting for the start
interrupt. This may lead to stray the reset work or the timer
after driver were removed.

Signed-off-by: Alexander Usyskin <alexander.usyskin@intel.com>
Signed-off-by: Tomas Winkler <tomas.winkler@intel.com>
Link: https://lore.kernel.org/r/20220215080438.264876-4-tomas.winkler@intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

The POWERING_DOWN state string was missing from
the device states list, add it.

Signed-off-by: Alexander Usyskin <alexander.usyskin@intel.com>
Signed-off-by: Tomas Winkler <tomas.winkler@intel.com>
Link: https://lore.kernel.org/r/20211223094705.204624-1-tomas.winkler@intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Introduce new intermediate state to allow the clients on the bus
to communicate with the firmware from the remove handler.
This is to enable to perform a clean shutdown.

Signed-off-by: Alexander Usyskin <alexander.usyskin@intel.com>
Signed-off-by: Tomas Winkler <tomas.winkler@intel.com>
Link: https://lore.kernel.org/r/20210206144325.25682-2-tomas.winkler@intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

This is to allow working with mei devices embedded within
another pci device, where mei device is represented
as a platform child device and fw status registers
are not necessarily resident in the device pci config space.

Bump the copyright year to 2019 on the modified files.

Signed-off-by: Tomas Winkler <tomas.winkler@intel.com>
Link: https://lore.kernel.org/r/20191106223841.15802-4-tomas.winkler@intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Expose mei device state to user-space through sysfs.
This gives indication to applications that driver is in transition,
usefully mostly to detect link reset state.

Signed-off-by: Alexander Usyskin <alexander.usyskin@intel.com>
Signed-off-by: Tomas Winkler <tomas.winkler@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Use unified version of the copyright notice in the files
Update copyright years according the year the files
were touched, except this patch and SPDX conversions.

Signed-off-by: Tomas Winkler <tomas.winkler@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Replace boiler plate licenses texts with the SPDX license
identifiers in the mei files header.

Signed-off-by: Tomas Winkler <tomas.winkler@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Implement circular buffer protocol over receive dma
buffer. Add extension to the mei message header that holds
length of the buffer on the dma buffer.

Signed-off-by: Tomas Winkler <tomas.winkler@intel.com>
Signed-off-by: Alexander Usyskin <alexander.usyskin@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Limit the number of queued writes per client.
Writes above this threshold are blocked till place
in the transmit queue is available.
The limit is configurable via sysfs and defaults to 50.
The implementation should provide blocking I/O behavior.
Prior to this change one would end up in the hands of OOM.

Signed-off-by: Alexander Usyskin <alexander.usyskin@intel.com>
Signed-off-by: Tomas Winkler <tomas.winkler@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

When mei driver is powering down due to suspend or shutdown
it will iterate over the mei client bus and disconnect
each client device attached in turn.
The power down flow consist of the link rest, which causes all clients
get disconnected at once, hence the individual disconnection
can be omitted and significantly reduce power down flow.

Signed-off-by: Tomas Winkler <tomas.winkler@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>