this changes the heuristics for UART TX DMA allocation to greatly
reduce the chances of DMA contention causing long delays on other
devices
This fixes issues with FETTec driver output and gimbal status messages
as reported by Amilcar and OlliW. The problem is particularly bad when
no GPS is connected to GPS1 on fmuv3 and derived boards (such as
CubeBlack)
key changes:
- remember the contention_counter across begin() calls, as the GPS
calls begin with new baudrates regularly
- added a is_shared() API to Shared_DMA, allowing the UART driver to
avoid TX DMA on shared streams when at low baudrates.
refactor rcout into separate thread and process all dshot requests there
move uart DMA completion to event model
process dshot locks in strick reverse order when unlocking
convert Shared_DMA to use mutexes
move UART transmit to a thread-per-uart
do blocking UART DMA transactions
do blocking dshot DMA transactions
trim stack sizes
cancel dma transactions on dshot when timeout occurs
support contention stats on blocking locking
move thread supression into chibios_hwdef.py
invalidate DMA bounce buffer correctly
separate UART initialisation into two halves
cleanup UART transaction timeouts
add @SYS/uarts.txt
move half-duplex handling to TX thread
correct thread statistics after use of ExpandingString
set unbuffered TX thread priority owner + 1
correctly unlock serial_led_send()
don't share IMU RX on KakuteF7Mini
observe dshot pulse time more accurately.
set TRBUFF bit for UART DMA transfers
deal with UART DMA timeouts correctly
don't deadlock on reverse ordered DMA locks
change PORT_INT_REQUIRED_STACK to 128
we can have multiple UARTs on the same thread sharing the same DMA TX
channel. That can lead to deadlock with blocking locks on DMA. This
makes UART requests for DMA locks non-blocking to fix the issue
this fixes a problem with the ICM-20789 on I2C where a reboot while the bus is active
leaves the IMU in a dead state where it can't be recovered without a power cycle.
Andrew Tridgell
Andy Piper
Mirko Denecke
Siddharth Purohit