The paradigm in the Flash classes is to wait for completion before performing the next operation to better pipeline commands. If there is a dependency that all flash operations must be complete prior to execution of a reset, then that dependency should be handled at a higher level. For example, change bossa.c to:

if (config.reset) {
// Ensure flash operation are complete prior to reset
flash->ready();
device.reset();
}

You'll need to add the ready() method to the Flash base class and implement it in each concrete class.

Closing this PR in favor of #151 which implements the correct Flash paradigm, as suggested above by @shumatech.