Serial detection was using serial_readline, which stripped carriage
return from the packets. This made for a very unreliable detection
mechanism.
Switch to a timeout-based detection mechanism that parses the data
as it comes in. This also allows us to stop parsing once we found
our first valid packet.
Signed-off-by: Alexandru Gagniuc <mr.nuke.me@gmail.com>
ols driver used to probe a series of available serial ports obtained
by regexp matching of common serial port names.
There are a number of problems with this approach:
1. It will probe all serial devices, including devices that do not
like to be probed, potentially causing them to act up.
2. It will try to probe serial ports which may already be opened in
other applications for other purposes.
3. It assumes the naming of the serial ports is set in stone, and
creates an unnecessary OS-specific list.
4. It produces unnecessary debug output even when an OLS device is
not connected.
5. etc...
Do not implicitly probe serial ports. Only probe the port specified
by the frontend, if any; otherwise, just quit.
Also get rid of all functionality in serial.c which was designed
specifically for random probing.
Signed-off-by: Alexandru Gagniuc <mr.nuke.me@gmail.com>
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.