SM6FBQ / HackRF clone - History

Initialise rf_path->switchctrl to SWITCHCTRL_SAFE.

This was previously never being initialised.

Remove extra call to switchctrl_set and global switchctrl variable.

This call is not required since the GPIOs are already configured in
rf_path_pin_setup(). The global switchctrl is not used anywhere else.

Initialise RF path GPIOs to safe settings.

Previously these calls were leaving the amplifiers on, since the
control settings passed were missing SWITCHCTRL_NO_TX_AMP_PWR and
SWITCHCTRL_NO_RX_AMP_PWR. Use the predefined SWITCHCTRL_SAFE here.

Also move these calls before setting the GPIO pins to output mode,
to avoid driving them to the wrong states briefly first.

Don't start baseband streaming until TX buffer is first filled.

Merge pull request #1103 from dizcza/master

fixed firmware manual build docs

Merge pull request #1166 from martinling/tx-disconnect-hang

Fix hang in TX when a libusb error occurs.

Merge pull request #1165 from greatscottgadgets/board-id-compat

libhackrf: #define outdated board IDs

Fix hang in TX when a libusb error occurs.

Where our callback is called with a status other than COMPLETED,
something abnormal has happened and we no longer want to either
submit further transfers or await a flush. So clear the streaming
and flush flags, and proceed to transfer_finished.

Do the same in the case where libusb_submit_transfer fails when
called to submit the flush transfer.