SM6FBQ / HackRF clone - History

Replace per-transfer flags with a count of active transfers.

This simplifies the code required to wait for cancellations to complete.
The condition variable now reflects whether `active_transfers == 0`, and
the associated lock must be held to decrement that count to zero.

Merge pull request #1070 from martinling/cleanup-stop

Remove unnecessary delays on stop, and duplicated stop commands on close.

Merge pull request #1069 from martinling/error-handling

Overhaul handling of transfer errors and use of streaming flag.

Merge pull request #1072 from martinling/fix-stack-variables

Fix USB requests that were responding with data from the stack.

Merge pull request #1106 from martinling/pll-startup

Implement NXP's recommended setup sequence for the PLL and M4 clock

Implement NXP's recommended setup sequence for the PLL and M4 clock.

This follows the sequence described in:

UM10503 Rev 2.4 (Aug 2018), section 13.2.1.1, page 167

Add an accurate delay loop.

The existing 'delay' function is not calibrated to any specific measure
of time. Add a new function using a loop with a known cycle count, to
produce delays of a given duration at a given CPU clock speed.

Jenkins CI (#1102)

* jenkins: initial commit

* jenkins: add missing usb hub check script

* jenkins: squish docker apt package install commands into a single command

* jenkins: fix type in Dockerfile

* jenkins: override interactive installations in Dockerfile (build-essentials fails due to tzdata)

* jenkins: set executable flag on ci scripts

* jenkins: remove sudo prefix from install scripts

* jenkins: add python3 venv to Dockerfile and build scripts

* jenkins: add missing python venv command to host install script

* jenkins: remove python install and venv redundancies

* jenkins: remove make install step, run hackrf tools directly from their build directory

* jenkins: re-add python3 and pip installations to docker because usbhub depends on them

* jenkins: add missing git install to docker

* jenkins: add python-is-python3 to docker's installed dependencies

* jenkins: use path string to specify the correct device for dfu-util

* jenkins: specify usbhub id for dual hub setup

* jenkins: turn unused usb hub ports off for testing

* jenkins: remove custom job throttle property

* use --disable-i2c usbhub option, install usbhub from latest, replace --privileged with cgroups option, remove redundancies from Dockerfile

* update device usb path for dfu-util

* remove apt/lists/* and fix typos

* ci: remove redundant environment setup in Jenkins

Merge pull request #1090 from veloman-yunkan/sweep_mode_bugfix

Bugfix in sweep mode when multiple blocks have to be read for each frequency