It is undefined behavior if stalling and unstalling clears an ongoing
transfer. Abort any ongoing transfers explicitly when stalling and
unstalling so the behavior is consistent across devices.
Remove the endpoint parameter from endpoint callbacks. This
information is redundant because endpoints are known at
construction time because they must be in the configuration
descriptor.
Only assert if disabled endpoints are used when USBDevice is
configured. USBDevice can leave the configured state due to a
reset at any time, which disables all endpoints. Because this
can happen at any time, thread processing could be performing
any endpoint operation. The endpoint operation should return
failure and do nothing in this case, rather than asserting
as this is not an application error.
An assert should only be triggered when an invalid endpoint is
used after the use of USBDevice acknoledges the switch to
configured mode by complete_set_configuration.
In specific this PR fixes the assert caused with the following
sequence:
-ISR: OUT event sent
-ISR: USB reset event
-ISR: USB configure request start
-Thread: OUT event processed on thread and next read starts
***endpoint is used while disabled causing an invalid assert***
-Thread: reset event processed
-Thread: configure event processed
This patch fixes this problem by making the following changes:
1. Operations done on disabled endpoints only assert when in the configured state
2. Adding and removing endpoints is only allowed when
the flag _endpoint_add_remove_allowed is set
3. The flag _endpoint_add_remove_allowed is set on the set
configuration request and cleared if the request is aborted or
fails
Remove calls to unlock which are not preceded by calls to lock.
Also move the location of the unlock underflow assert so unbalanced
unlocking during post processing is caught.
Add a destructor to USBDevice to ensure that resources have been
properly released. Additionally add an assert in the destructor that
deinit has already been called. If it has not been called then
interrupts can still occur which may cause a crash.
Remove the option to block in USBDevice::connect since this
should be handled at a higher level. Also call init to ensure that
the USBDevice has been initalized.
Add the helper function endpoint_remove_all which removes all added
endpoints. This is useful for class drivers switching between
different USB configurations.
Stalling endpoint 0 indicates the end of a control transfer.
Return immediately when this occurs rather than continuing processing.
In particular, this patch prevents status from erroneously being
sent when _request_setup returns false inside _complete_request.
Perform processing triggered by user callbacks when USB is being
unlocked rather than synchronously. This prevents recursive callbacks
which reduces stack usage. This also prevents state change inside
the user callback which makes the code easier to reason about.
Initialize the _transfer structure so the behavior is the same
regardless of prior memory contents. This fixes a hang during
USB testing when CI flags are used.
Remove the USBDevice function read_start and automatically start all
reads internally in USBDevice. This patch also renames the function
read_finish to read.
Russ Butler
Russ Butler
Maciej Bocianski