Only when dynamic USB devices are enabled.
The issue here is that when the USB reset triggers, the dynamic USB device
reset callback is called from inside the TinyUSB task.
If that callback tries to print something then it'll call through to
tud_cdc_write_flush(), but TinyUSB hasn't finished updating state yet to
know it's no longer configured. Subsequently it may try to queue a transfer
and then the low-level DCD layer panics.
By explicitly stalling the endpoint first, usbd_edpt_claim() will fail and
tud_cdc_write_flush() returns immediately.
This work was funded through GitHub Sponsors.
Signed-off-by: Angus Gratton <angus@redyak.com.au>
In the case where an OUT control transfer triggers with wLength==0 (i.e.
all data sent in the SETUP phase, and no additional data phase) the
callbacks were previously implemented to return b"" (i.e. an empty buffer
for the data phase).
However this didn't actually work as intended because b"" can't provide a
RW buffer (needed for OUT transfers with a data phase to write data into),
so actually the endpoint would stall.
The symptom was often that the device process the request (if processing
it in the SETUP phase when all information was already available), but the
host sees the endpoint stall and eventually returns an error.
This commit changes the behaviour so returning True from the SETUP phase of
a control transfer queues a zero length status response.
Signed-off-by: Angus Gratton <angus@redyak.com.au>
Updates a few code comments that were out of date or poorly worded. No code
changes.
This work was funded through GitHub Sponsors.
Signed-off-by: Angus Gratton <angus@redyak.com.au>
Previously, constructing the singleton USBDevice object was enough to
trigger a USB disconnect on soft reset. Now it also has to be active.
The only case where this changes the behaviour is if the USBDevice object
has been constructed but never set to active (no more disconnect in this
case). Otherwise, behaviour is the same.
This change was requested by hippy on the raspberrypi forums.
This work was funded through GitHub Sponsors.
Signed-off-by: Angus Gratton <angus@redyak.com.au>
This new machine-module driver provides a "USBDevice" singleton object and
a shim TinyUSB "runtime" driver that delegates the descriptors and all of
the TinyUSB callbacks to Python functions. This allows writing arbitrary
USB devices in pure Python. It's also possible to have a base built-in
USB device implemented in C (eg CDC, or CDC+MSC) and a Python USB device
added on top of that.
This work was funded through GitHub Sponsors.
Signed-off-by: Angus Gratton <angus@redyak.com.au>
