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.
this fixes a problem with the automatic DMA disable on DMA contention
in UARTs. This fixes issue #14581
the problem was that while tx_dma_enabled was correctly set to false,
it would keep looping inside write_pending_bytes_DMA() if the data
arrived in the write buffer at a faster rate than it could be sent
out, which did happen with a mavlink stream rate of 4Hz. This means it
kept using DMA even with tx_dma_enabled set to false. The result was
that the automatic flow control code never got a chance to run and we
didn't switch back to non-DMA for these low baudrate contended UARTs
this gains about 20k of RAM, and has almost no impact on log download
speed at 921600 on a F427. The improved threading means we can afford
to have smaller buffers
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
When hw flow control is enabled check the CTS pin before we grab the
DMA channel to prevent a long timeout trying to send to a blocked port
from holding a DMA channel against another device
this fixes issue #16587
when a peripheral is made available via BRD_ALT_CONFIG we need to
remap the existing ioline_t in the UART and I2C drivers to use the new
pin.
This fixes an issue with half-duplex, inverted, swapped UART pins for
protocols like FPort and FPort2
this fixes an issue seen on one board which caused a watchdog on high
uart DMA load. We have reproduced the issue on another board by
forcing a very high DMA transfer rate on the same DMA channel while
also requesting very high transfer rates on the UART. The likely race
is in the DMA transmit timeout code, and the simplest fix is to lock
out interrupts during the DMA setup to ensure the tx timeout cannot
trigger during the setup
this fixes an issue with single byte writes with half duplex. It isn't
an elegent solution, but nicely separates the different types of half
duplex operation
to prevent output bytes being seen as input bytes we disable half
duplex during transmit. This was previously only done for non-inverted
UARTs. This patch enables it whether we are inverted or not. This
greatly reduces the number of bad input bytes.
this caused a failure to boot on some boards if they tried to print
messages in early startup code before hal was initialised
thanks to @Shadowru for reporting the issue
this fixes an issue with log download on USB and mavlink throughput
caused lock contention. The issue was introduced with the changes for
unbuffered writes recently (does not affect stable releases)
Andrew Tridgell
Andy Piper
Siddharth Purohit
Peter Barker
Mirko Denecke