Sending an SR_DF_META packet at the start of every stream is not
mandatory; the frontend should ask for what it needs, and any extra
information the driver wants to send will come in due time.
Currently hw_info_get() can receive requests for entries (info_id) that
the specific driver doesn't support. That is (right now) a valid
use-case and not an error (might change later, though).
Thus, for now, don't output messages for such requests at all (certainly
not as sr_err() where they show up in e.g. sigrok-cli output per default).
In the case of USB drivers, a driver's dev_acquisition_stop() cannot
simply remove its fd sources from the session and close its devices:
a USB transfer might still be underway, and it needs to be finished
(and its memory freed) properly.
An sr_dev_inst->status value is added: SR_ST_STOPPING, which should
be set when the driver's dev_acquisition_stop() is called, and acts
as a marker for the USB event handler to wind up its operations.
In order for dev_acquisition_stop() to be able to set the sdi status,
however, it needs to be unconstified.
Bert Vermeulen
Uwe Hermann
Peter Stuge