this greatly speeds up MAVFtp on USB connections.
Downloading a log file without this change on a CubeOrange gets around
16 kbyte/s. With this change I get over 480 kbyte/s, a factor of 30x
speedup
e.g.:
./Tools/autotest/vehicle_test_suite.py:8607:89: B006 Do not use mutable data structures for argument defaults. They are created during function definition time. All calls to the function reuse this one instance of that data structure, persisting changes between them.
Don't get its path unless we are about to generate it to avoid an
inaccurate list of generated files. Do this by keeping track of the path
in a variable instead of checking for the result on the filesystem.
This is somewhat strange and mixed in with the romfs file and
AP_Param.cpp, to disentangle later...
This will allow waf to avoid cleaning them and avoid unnecessary
regenerations.
Some slight changes to centralize the use of the output directory are
also performed.
The read buffer must be invalidated after a DMA read operation as
nothing guarantees an invalidation before the operation finishes
persists until after it's complete.
Quoth the ARM ARMv7M ARM (Architecture Reference Manual): "Entries for
addresses with a Normal Cacheable attribute can be allocated to an
enabled cache at any time, and so the cache invalidate operation cannot
ensure that the address is not present in an enabled cache."
Due to considerations surrounding how the buffer is actually used, we
end up needing an invalidate before and flush after the read op.
Not handling this correctly manifested as rampant dataflash corruption
using LittleFS on KakuteH7Mini (commit 33631df2) due to the driver not
seeing "busy" responses when polling the dataflash chip and having
written data be ignored. This scenario was, however, very fragile, and
everything worked correctly for some alignments of MCU code flash,
presumably creating different timing or cache influences.
It's not clear where else this could have caused an issue, the LittleFS
poll loop is perhaps unique in writing one byte then reading one byte.
Nevertheless, careful investigation with a debugger and logic analyzer,
along with understanding of the manuals, justify this as a proper fix
(and of course the corruption no longer manifests).
Bob Long
Peter Barker
Andy Piper
Sai Vishnu Balaji
Andrew Tridgell
Alexis Guijarro
Thomas Watson
mehmetmydn
MinderringandHenry Wurzburg
Iampete1
Maxim Buzdalov
jobs
Tom Pittenger
shen
Serhii Marchuk