Ensures consistent behaviour and resolves the D-Cache bug (the "exhaustive"
argument being lost due to cache being turned off) when O0 is used.
The changes in this commit are:
- Change -O0 to -Os because "gcc is considered broken at -O0" according to
https://github.com/ARM-software/CMSIS_5/issues/620#issuecomment-550235656
- Use volatile for mem_base so the compiler doesn't optimise away reads or
writes to the SDRAM, which is being tested.
- Use DSB to prevent any other compiler optimisations that would change the
testing logic.
- Use alternating pattern/antipattern in exhaustive test to catch more
hardware/configuration errors.
Implementation adapted by @andrewleech, taken directly from investigation
by @iabdalkader and @dpgeorge.
See #7841 and #7869 for further discussion.
The H743 has equal sized pages of 128k, which means the filesystem doesn't
need to be near the beginning. This commit moves the filesystem to the
very end of flash, and extends it to 512k (4 pages).
Signed-off-by: Damien George <damien@micropython.org>
This change adds the OLIMEX H407 support to the STM32 port. The H407
(https://www.olimex.com/Products/ARM/ST/STM32-H407/) is simliar to the
already existing E407
(https://www.olimex.com/Products/ARM/ST/STM32-E407) but does not support
Ethernet and has a full-size USB-A port instead of a Mini-USB socket.
Both boards use the STM32F407ZGT6 CPU.
This port is basically a copy of the E407 but with changed pinmux:
* Removed Ethernet pin definition
* Removed UART1 (pins are used for other functions)
* Removed UART3 flow control pins (pins are used for other functions)
* Removed SD-Card detect pin (since it is not connected on the H407)
A REPL on UART3 is connected to the U3BOOT-header, a 3-pin header with RX,
TX and GND that is intended for the serial terminal.
Tested:
* Micro-SD Card is detected when inserted on RESET
* REPL on UART3 works
* Serial port on the mini USB socket
Signed-off-by: Chris Fiege <cfi@pengutronix.de>
This commit removes all parts of code associated with the existing
MICROPY_OPT_CACHE_MAP_LOOKUP_IN_BYTECODE optimisation option, including the
-mcache-lookup-bc option to mpy-cross.
This feature originally provided a significant performance boost for Unix,
but wasn't able to be enabled for MCU targets (due to frozen bytecode), and
added significant extra complexity to generating and distributing .mpy
files.
The equivalent performance gain is now provided by the combination of
MICROPY_OPT_LOAD_ATTR_FAST_PATH and MICROPY_OPT_MAP_LOOKUP_CACHE (which has
been enabled on the unix port in the previous commit).
It's hard to provide precise performance numbers, but tests have been run
on a wide variety of architectures (x86-64, ARM Cortex, Aarch64, RISC-V,
xtensa) and they all generally agree on the qualitative improvements seen
by the combination of MICROPY_OPT_LOAD_ATTR_FAST_PATH and
MICROPY_OPT_MAP_LOOKUP_CACHE.
For example, on a "quiet" Linux x64 environment (i3-5010U @ 2.10GHz) the
change from CACHE_MAP_LOOKUP_IN_BYTECODE, to LOAD_ATTR_FAST_PATH combined
with MAP_LOOKUP_CACHE is:
diff of scores (higher is better)
N=2000 M=2000 bccache -> attrmapcache diff diff% (error%)
bm_chaos.py 13742.56 -> 13905.67 : +163.11 = +1.187% (+/-3.75%)
bm_fannkuch.py 60.13 -> 61.34 : +1.21 = +2.012% (+/-2.11%)
bm_fft.py 113083.20 -> 114793.68 : +1710.48 = +1.513% (+/-1.57%)
bm_float.py 256552.80 -> 243908.29 : -12644.51 = -4.929% (+/-1.90%)
bm_hexiom.py 521.93 -> 625.41 : +103.48 = +19.826% (+/-0.40%)
bm_nqueens.py 197544.25 -> 217713.12 : +20168.87 = +10.210% (+/-3.01%)
bm_pidigits.py 8072.98 -> 8198.75 : +125.77 = +1.558% (+/-3.22%)
misc_aes.py 17283.45 -> 16480.52 : -802.93 = -4.646% (+/-0.82%)
misc_mandel.py 99083.99 -> 128939.84 : +29855.85 = +30.132% (+/-5.88%)
misc_pystone.py 83860.10 -> 82592.56 : -1267.54 = -1.511% (+/-2.27%)
misc_raytrace.py 21490.40 -> 22227.23 : +736.83 = +3.429% (+/-1.88%)
This shows that the new optimisations are at least as good as the existing
inline-bytecode-caching, and are sometimes much better (because the new
ones apply caching to a wider variety of map lookups).
The new optimisations can also benefit code generated by the native
emitter, because they apply to the runtime rather than the generated code.
The improvement for the native emitter when LOAD_ATTR_FAST_PATH and
MAP_LOOKUP_CACHE are enabled is (same Linux environment as above):
diff of scores (higher is better)
N=2000 M=2000 native -> nat-attrmapcache diff diff% (error%)
bm_chaos.py 14130.62 -> 15464.68 : +1334.06 = +9.441% (+/-7.11%)
bm_fannkuch.py 74.96 -> 76.16 : +1.20 = +1.601% (+/-1.80%)
bm_fft.py 166682.99 -> 168221.86 : +1538.87 = +0.923% (+/-4.20%)
bm_float.py 233415.23 -> 265524.90 : +32109.67 = +13.756% (+/-2.57%)
bm_hexiom.py 628.59 -> 734.17 : +105.58 = +16.796% (+/-1.39%)
bm_nqueens.py 225418.44 -> 232926.45 : +7508.01 = +3.331% (+/-3.10%)
bm_pidigits.py 6322.00 -> 6379.52 : +57.52 = +0.910% (+/-5.62%)
misc_aes.py 20670.10 -> 27223.18 : +6553.08 = +31.703% (+/-1.56%)
misc_mandel.py 138221.11 -> 152014.01 : +13792.90 = +9.979% (+/-2.46%)
misc_pystone.py 85032.14 -> 105681.44 : +20649.30 = +24.284% (+/-2.25%)
misc_raytrace.py 19800.01 -> 23350.73 : +3550.72 = +17.933% (+/-2.79%)
In summary, compared to MICROPY_OPT_CACHE_MAP_LOOKUP_IN_BYTECODE, the new
MICROPY_OPT_LOAD_ATTR_FAST_PATH and MICROPY_OPT_MAP_LOOKUP_CACHE options:
- are simpler;
- take less code size;
- are faster (generally);
- work with code generated by the native emitter;
- can be used on embedded targets with a small and constant RAM overhead;
- allow the same .mpy bytecode to run on all targets.
See #7680 for further discussion. And see also #7653 for a discussion
about simplifying mpy-cross options.
Signed-off-by: Jim Mussared <jim.mussared@gmail.com>
Any external user of DMA (eg a board with a custom DMA driver) must call
dma_external_acquire() for their DMA controller/stream to ensure that the
DMA clock is not automatically turned off while it's still being used
externally.
Signed-off-by: Damien George <damien@micropython.org>
This change allows a CPU pin to be hidden from the user by prefixing it
with a "-" in the pins.csv file for a board. It will still be available in
C code, just not exposed to Python.
Signed-off-by: Damien George <damien@micropython.org>
Don't want users to accidentally use boot.py (because recovering requires
knowing how to activate safe mode).
Signed-off-by: Jim Mussared <jim.mussared@gmail.com>
This commit is based upon prior work of @dpgeorge and @koendv.
MCU support for the STM32H7A3 and B3 families MCUs:
- STM32H7A3xx
- STM32H7A3xxQ (SMPS)
- STM32H7B3xx
- STM32H7B3xxQ (SMPS)
Support has been added for the STM32H7B3I_DK board.
Signed-off-by: Jan Staal <info@janstaal.com>
To simplify the socket state.
The CC3K driver (see drivers/cc3000/inc/socket.h and src/socket.c) has
socket() returning an INT16 so there is now enough room to store it
directly in the fileno member.
The zephyr port doesn't support SoftI2C so it's not enabled, and the legacy
I2C constructor check can be removed.
Signed-off-by: Damien George <damien@micropython.org>
To keep things neat and tidy, we ensure that each file has 1 and only 1
newline at the end of each file.
Signed-off-by: David Lechner <david@pybricks.com>
A board can now define the following to fully customise the extended block
device interface provided by the storage sub-system:
- MICROPY_HW_BDEV_BLOCKSIZE_EXT
- MICROPY_HW_BDEV_READBLOCKS_EXT
- MICROPY_HW_BDEV_WRITEBLOCKS_EXT
- MICROPY_HW_BDEV_ERASEBLOCKS_EXT
Signed-off-by: Damien George <damien@micropython.org>
This commit creates a new stm32 board for the NUCLEO_H743ZI2, which is the
current version of this from ST. This is a modified copy of the
NUCLEO_H743ZI board, and the ZI2 board differs in a few minor ways:
- LED2 has moved from PB7 to PE1 and is now yellow rather than blue
- the USB power enable has moved from PG6 to PG10
- the USER button is now pulled down
This allows changing the frequency to: 100kHz, 200kHz, 400kHz, 800kHz,
1MHz, 2MHz, 4MHz, 8MHz, 16MHz, 32MHz, 64MHz. For frequencies 2MHz and
below, low power run (LPR) mode is enabled automatically.
Signed-off-by: Damien George <damien@micropython.org>
For consistency with other board-level config macros that begin with
MICROPY_HW_USB.
Also allow boards in the mimxrt, nrf and samd ports to configure these
values.
Signed-off-by: Damien George <damien@micropython.org>
Add basic support for LEGO HUB NO.6 (e.g. LEGO SPIKE Prime, LEGO MINDSTORMS
Robot Inventor).
See README.md for details.
Thanks to @dpgeorge for helping put this together.
Signed-off-by: Tobias Thyrrestrup <tt@LEGO.com>
It needs to use a different function because the formula to compute the
baudrate on LPUART1 is different to a normal UART.
Fixes issue #7466.
Signed-off-by: Damien George <damien@micropython.org>
* Make SDRAM test cache-aware for newer MCUs.
* Use the defined data bus width (instead of the fixed 8-bits).
* Allow optional failure on error with verbose error messages.
* Test speed is now inverted (test accepts exhaustive instead fast).
Call MICROPY_EVENT_POLL_HOOK even on very short delays so that busy loops
that call sleep_ms still yield to events and other threads.
See related issue #5344.
Replace "master" with "controller" and "slave" with "peripheral" in
comments, errors, and debug messages.
Add CONTROLLER and PERIPHERAL constants to pyb.SPI and pyb.I2C classes;
retain MASTER and SLAVE constants for backward compatiblity.
This commit adds I2S protocol support for the esp32 and stm32 ports, via
a new machine.I2S class. It builds on the stm32 work of blmorris, #1361.
Features include:
- a consistent I2S API across the esp32 and stm32 ports
- I2S configurations supported:
- master transmit and master receive
- 16-bit and 32-bit sample sizes
- mono and stereo formats
- sampling frequency
- 3 modes of operation:
- blocking
- non-blocking with callback
- uasyncio
- internal ring buffer size can be tuned
- documentation for Pyboards and esp32-based boards
- tested on the following development boards:
- Pyboard D SF2W
- Pyboard V1.1
- ESP32 with SPIRAM
- ESP32
Signed-off-by: Mike Teachman <mike.teachman@gmail.com>
The ADC_FIRST_GPIO_CHANNEL and ADC_LAST_GPIO_CHANNEL macros are no longer
needed. Instead the pin_adcX table (X = 1, 2, 3) is now generated to be
the exact size needed for a given MCU, and MP_ARRAY_SIZE(pin_adcX) is used
to determine the upper bound.
This commit also allows CPU pins to be excluded from ADC configuration if
they are hidden by prefixing their name with a "-".
Signed-off-by: Damien George <damien@micropython.org>
* Modify common functions in adc.c to accept ADC handle.
* Most external channels are connected to ADC12 which is used by default.
* For ADCAll (internal channels) ADC3 is used instead.
* Issue #4435 is possibly related (at least partially fixed).
This adds a call to mp_deinit() in the main function of the STM32 port.
This enables the use of MICROPY_PORT_DEINIT_FUNC on that port, as well as
cleaning up the GIL if threading is enabled.
Previous behaviour was: if boot.py had an exception then main.py would
still run, which is arguably unexpected behaviour.
This commit changes the behaviour so main.py is not run if boot.py has an
error.
Signed-off-by: Damien George <damien@micropython.org>
It reschedules the BT HCI poll soft timer so that it is called exactly when
the next timer expires.
Signed-off-by: Damien George <damien@micropython.org>
Instead of using systick the BT subsystem is now scheduled using a soft
timer. This means it is scheduled only when it is enabled.
Signed-off-by: Damien George <damien@micropython.org>
And call mp_pairheap_init_node() in soft_timer_static_init() so that
reinsert can be called after static_init.
Signed-off-by: Damien George <damien@micropython.org>
This introduces a new macro to get the main thread and uses it to ensure
that asynchronous exceptions such as KeyboardInterrupt (CTRL+C) are only
scheduled on the main thread. This is more deterministic than being
scheduled on a random thread and is more in line with CPython that only
allow signal handlers to run on the main thread.
Fixes issue #7026.
Signed-off-by: David Lechner <david@pybricks.com>
This moves mp_pending_exception from mp_state_vm_t to mp_state_thread_t.
This allows exceptions to be scheduled on a specific thread.
Signed-off-by: David Lechner <david@pybricks.com>
With GCC 11 there is now a warning about array bounds of OTP-mac, due to
the OTP being a literal address.
Signed-off-by: Damien George <damien@micropython.org>
Leaving the bootloader from an IRQ (eg USB or I2C IRQ) will not work if
MBOOT_LEAVE_BOOTLOADER_VIA_RESET is disabled, ie if mboot jumps directly to
the application. This is because the CPU will still be in IRQ state when
the application starts and IRQs of lower priority will be blocked.
Fix this by setting a flag when the bootloader should finish, and exit the
bootloader always from the main (top level) thread.
This also improves the USB behaviour of mboot: it no longer abruptly
disconnects when the manifest command is sent.
Signed-off-by: Damien George <damien@micropython.org>
RX and CTS are the input pins and pull-ups are enabled so they don't cause
a problem if left unconnected. But the output pins don't need a pull up
(they were originally all configured with pull up in commit
8f7491a109).
If needed, the pull-ups can be disabled in Python using machine.Pin after
the UART is constructed.
See issue #4369.
Signed-off-by: Damien George <damien@micropython.org>
The DMA driver will turn off DMA if it hasn't been used for an amount of
time (to save power). The SDIO driver for cyw43 WLAN was not informing the
DMA driver that it was using DMA and there was a chance that the DMA would
turn off in the middle of an SDIO DMA transfer. The symptoms of this would
be printing of SDIO error messages and a failure to communicate with the
cyw43 WLAN module.
This commit fixes this issue by changing the SDIO driver to use the
dma_nohal_XXX API to initialise and start the DMA.
Signed-off-by: Damien George <damien@micropython.org>
A board can now customise mboot with:
- MBOOT_LED1, MBOOT_LED2, MBOOT_LED3, MBOOT_LED4: if it needs to have
different LEDs for mboot compared to the application
- MBOOT_BOARD_LED_INIT: if it needs a fully customised LED init function
- MBOOT_BOARD_LED_STATE: if it needs a fully customised LED state-setting
function
- MBOOT_BOARD_GET_RESET_MODE: if it needs a fully customised function to
get the reset mode
With full customisation, the only requirement is a single LED to show the
status of the bootloader (idle, erasing, flashing, etc), which can be
configured to do nothing if needed.
Signed-off-by: Damien George <damien@micropython.org>
It is enabled by default to get the standard behaviour of doing a reset
after it is finished, but can be disabled by a board to jump straight to
the application (likely the board needs to use MBOOT_BOARD_CLEANUP to make
this work).
The application is passed a reset mode of BOARDCTRL_RESET_MODE_BOOTLOADER
if the bootloader was active and entered via a jump.
Signed-off-by: Damien George <damien@micropython.org>
This new logic is equivalent to the old logic when the only possibilities
for reset_mode are NORMAL, SAFE_MODE and FILESYSTEM, which is the standard
case. But the new logic also allows other reset_mode values (eg
BOOTLOADER) to run boot.py and main.py.
Signed-off-by: Damien George <damien@micropython.org>
When disabled the bootloader is entered via a direct jump. When enabled
the bootloader is entered via a system reset then a jump. It's enabled by
default to retain the existing behaviour, which is the recommended way.
Signed-off-by: Damien George <damien@micropython.org>
This can now be selected by setting MICROPY_HW_SDIO_SDMMC, which defaults
to 1, ie SDMMC1. The pins can also be selected and default to the standard
C8/C9/C10/C11/C12/D2.
This can now be selected by setting MICROPY_HW_SDCARD_SDMMC, which defaults
to 1, ie SDMMC1. This commit also renames the SD pin configuration macros
from MICROPY_HW_SDMMC2_xxx to MICROPY_HW_SDCARD_xxx, as well as renaming
MICROPY_HW_SDMMC_BUS_WIDTH to MICROPY_HW_SDCARD_BUS_WIDTH.
Signed-off-by: Damien George <damien@micropython.org>
A board can now define MBOOT_TEXT0_ADDR to place mboot at a location other
than 0x08000000. This can be useful if, for example, there is already a
different bootloader on the device.
Signed-off-by: Damien George <damien@micropython.org>
A board can now define MBOOT_LD_FILES (at the Makefile-level) to specify
custom linker scripts. And stm32_generic.ld has been split into 2 pieces
so one or the other can be reused (usually stm32_sections.ld wolud be
reused by a board, and stm32_memory.ld redefined).
Signed-off-by: Damien George <damien@micropython.org>
A board can now use BUILDING_MBOOT at the Makefile-level to do things
conditional on building mboot, for example add source files to SRC_C.
Signed-off-by: Damien George <damien@micropython.org>
Commit 1e297c8898 introduced a bug where the
very first reset-mode state on the LEDs was not shown, because prior to
that commit the first reset-mode state was the same as the initial LED
state (green on, others off) and update_reset_mode() was called after
setting this initial LED state.
This is fixed in this commit by changing the update_reset_mode() loop so
that it displays the current reset mode before doing the delay.
Signed-off-by: Damien George <damien@micropython.org>
And use the same boardctrl.h header for both the application and mboot so
these constants are consistent.
Signed-off-by: Damien George <damien@micropython.org>
This adds support for making static (ie not on the Python GC heap) soft
timers. This can be useful for a board to define a custom background
handler, or eventually for BLE/network processing to use instead of systick
slots; it will be more efficient using soft timer for this.
The main issue with using the existing code for static soft timers is that
it would combine heap allocated and statically allocated soft_timer_entry_t
instances in the same pairing-heap data structure. This would prevent the
GC from tracing some of the heap allocated entries (because the GC won't
follow pointers outside the heap).
This commit makes it so that soft timer entries are explicitly marked,
instead of relying on implicit marking by having the root of the pairing
heap in the root pointer section. Also, on soft reset only the heap-
allocated soft timers are deleted from the pairing heap, leaving the
statically allocated ones.
Signed-off-by: Damien George <damien@micropython.org>
Improvements are:
- Default period is 1000ms with callback disabled.
- if period is not specified then it's not updated (previously, if period
was not specified then it was set to -1 and running the timer callback as
fast as possible, making the REPL unresponsive).
- Use uint64_t to compute delta_ms, and raise a ValueError if the period is
too large.
- If callback is not specified then it's not updated.
- Specifying None for the callback will disable the timer.
Signed-off-by: Damien George <damien@micropython.org>
This function includes the UART prescaler in the calculation (if it has
one, eg on H7 and WB MCUs).
Signed-off-by: Damien George <damien@micropython.org>
The STM32WB has a problem when address resolution is enabled: under certain
conditions the MCU can get into a state where it draws an additional 10mA
or so and eventually ends up with a broken BLE RX path in the silicon. A
simple way to reproduce this is to enable address resolution (which is the
default for NimBLE) and start the device advertising. If there is enough
BLE activity in the vicinity then the device will at some point enter the
bad state and, if left long enough, will have permanent BLE RX damage.
STMicroelectronics are aware of this issue. The only known workaround at
this stage is to not enable address resolution, which is implemented by
this commit.
Work done in collaboration with Jim Mussared aka @jimmo.
Signed-off-by: Damien George <damien@micropython.org>
Prior to this commit, if C2 was busy (eg lots of BLE activity) then it may
not have had time to respond to the notification on the IPCC_CH_MM channel
by the time additional memory was available to put on that buffer. In such
a case C1 would modify the free buffer list while C2 was potentially
accessing it, and this would eventually lead to lost memory buffers (or a
corrupt linked list). If all buffers become lost then ACL packets
(asynchronous events) can no longer be delivered from C2 to C1.
This commit fixes this issue by waiting for C2 to indicate that it has
finished using the free buffer list.
Work done in collaboration with Jim Mussared aka @jimmo.
Signed-off-by: Damien George <damien@micropython.org>
STM32L476RG MCU of NUCLEO_L476RG board has 6 UART/USART units in total
(USART1, USART2, USART3, UART4, UART5 and LPUART1), but only UART2,
connected to REPL, was defined and available in Python code.
Defined are all 5 remaining UART/USART units including LPUART1.
Signed-off-by: Alexander Ziubin aziubin@googlemail.com
This commit simplifies the customisation of the main MicroPython execution
loop (4 macros are reduced to 2), and allows a board to have full control
over the execution (or not) of boot.py and main.py.
For boards that use the default start-up code, there is no functional
change in this commit.
Signed-off-by: Damien George <damien@micropython.org>
Support for C++ was added in 97960dc7de but
that commit didn't include the C++ exception handling table in the binary
firmware image. This commit fixes that.
Signed-off-by: Damien George <damien@micropython.org>
The GNU Make dir command uses spaces as item separator so it does not
work for e.g building the STM32 port on Cygwin with a default Arm
installation in "c:/program files (x86)/GNU Arm Embedded Toolchain".
Fix by using POSIX dirname on a quoted path instead.
This allows the user to enable wake-up sources using the EWUP bits, on F7
MCUs.
Disabling the wake-up sources while clearing the wake-up flags follows the
reference manual and ST examples.
state.reset_mode is updated by `MICROPY_BOARD_BEFORE_SOFT_RESET_LOOP` but
not passed to `init_flash_fs`, and so factory reset is not executed on
boards that do not have a bootloader. This bug was introduced by
4c3976bbcaFixes#6903.
A corrupt filesystem may lead to a request for a block which is out of
range of the block device limits. Return an error instead of passing the
request down to the lower layer.
Two of the defaults have also changed in this commit:
- MICROPY_HW_RFCORE_BLE_LSE_SOURCE changed from 1 to 0, which configures
the LsSource to be LSE (needed due to errata 2.2.1).
- MICROPY_HW_RFCORE_BLE_VITERBI_MODE changed from 0 to 1, which enables
Viterbi mode, following all the ST examples.
Signed-off-by: Damien George <damien@micropython.org>
These ports already have uzlib enabled so this additional ubinascii.crc32
function only costs about 90 bytes of flash.
Signed-off-by: Damien George <damien@micropython.org>
Add LPUART1 as a standard UART. No low power features are supported, yet.
LPUART1 is enabled as the next available UART after the standard U(S)ARTs:
STM32WB: LPUART1 = UART(2)
STM32L0: LPUART1 = UART(6)
STM32L4: LPUART1 = UART(6)
STM32H7: LPUART1 = UART(9)
On all ports: LPUART1 = machine.UART('LP1')
LPUART1 is enabled by defining MICROPY_HW_LPUART1_TX and
MICROPY_HW_LPUART1_RX in mpconfigboard.h.
Signed-off-by: Chris Mason <c.mason@inchipdesign.com.au>
So that mboot can be used to program encrypted/signed firmware to regions
of flash that are not the main application, eg that are the filesystem.
Signed-off-by: Damien George <damien@micropython.org>
The default for these is to enable them, but they can now be disabled
individually by a board configuration.
Signed-off-by: Damien George <damien@micropython.org>
If a board defines USBD_VID then that will be used instead of the default.
And then the board must also define all USBD_PID_xxx values that it needs.
Signed-off-by: Damien George <damien@micropython.org>
This allows changing the baudrate of the UART without reinitialising it
(reinitialising can lead to spurious characters sent on the TX line).
Signed-off-by: Damien George <damien@micropython.org>
To simplify config, there's no need to specify MP_PLAT_PRINT_STRN if it's
the same as the default definition in py/mpconfig.h.
Signed-off-by: Damien George <damien@micropython.org>
With mboot encrpytion and fsload enabled, the DEBUG build -O0 compiler
settings result in mboot no longer fitting in the 32k sector. This commit
changes this to -Og which also brings it into line with the regular stm32
build.
MCUs with device-only USB peripherals (eg L0, WB) do not implement (at
least not in the ST HAL) the HAL_PCD_DisconnectCallback event. So if a USB
cable is disconnected the USB driver does not deinitialise itself
(usbd_cdc_deinit is not called) and the CDC driver can stay in the
USBD_CDC_CONNECT_STATE_CONNECTED state. Then if the USB was attached to
the REPL, output can become very slow waiting in usbd_cdc_tx_always for
500ms for each character.
The disconnect event is not implemented on these MCUs but the suspend event
is. And in the situation where the USB cable is disconnected the suspend
event is raised because SOF packets are no longer received.
The issue of very slow output on these MCUs is fixed in this commit (really
worked around) by adding a check in usbd_cdc_tx_always to see if the USB
device state is suspended, and, if so, breaking out of the 500ms wait loop.
This should also help all MCUs for a real USB suspend.
A proper fix for MCUs with device-only USB would be to implement or somehow
synthesise the HAL_PCD_DisconnectCallback event.
See issue #6672.
Signed-off-by: Damien George <damien@micropython.org>
