Slow upload over USB on cygwin to pixracer

[RaphZufferey]

Describe the bug
Upload speed to pixracer is very slow.

To Reproduce
Steps to reproduce the behavior:

1. Cygwin on Windows 10
2. Pixracer connected via USB, COM port setup as 2 and baudrate 115200 or 57600
3. upload with "make px4_fmu-v4 upload"

Expected behavior
Upload in 30s, speed that I usually get on Ubuntu build

Log Files and Screenshots

Additional context
Bug #10429 still happens irregularly, about 1/3 of trials to upload. Just hangs on "non-standard ... USB connection"

[MaEtUgR]

I can reproduce with two times the exact same setup and firmware (latest master).
Windows 10 Cygwin toolchain:

Ubuntu 18.04 VM on Windows:

Sorry but I have no idea why that could be. @julianoes @davids5 any pointers for me to look into?
Maybe it's again the windowed mode that kicks in, I can check that.

[davids5]

@MaEtUgR - even though it says ttyS3 am I correct to assume this is all USB?

The display says windows mode is false.

Here is a quick test - set the baud rate to the highest rate supported rate on Cygwin and see if it changes the time.

This may be the original issue the OS time quanta per packet delay that I was seeing originally.

[MaEtUgR]

@davids5 Yes, it's USB serial devices which are COM ports on Windows and these COM ports get mapped to /dev/ttyS# in Cygwin for posix compliance. Let me check your suggested test.

[MaEtUgR]

@david5 I checked and either I change the wrong thing or it doesn't make any difference when I change the bootloader baudrate. I checked the args.baud_bootloader on line https://github.com/PX4/Firmware/blob/be02ad3514213af7e1febd0377835eb00d063495/Tools/px_uploader.py#L815 and it makes no difference. When I change baud_flightstack it doesn't reboot anymore which is to be expected and means I'm not at the wrong spot.

What's also interesting is: on fmu-v5 I don't see that much of a difference in flashing time between
Cygwin (Windows):

Ubuntu 18.04 (VM on Windows):

[MaEtUgR]

On the pixracer I now also have a normal upload time using Windows Cygwin...:

Did something change on master?
@RaphZufferey Does the problem persist for you?

[RaphZufferey]

I don't have a pixracer on hand right now, will try as soon as possible! Do you also get normal compiling speeds? It takes about 4-5 minutes to clean build the code for me.
Thanks a lot for all the help.

[davids5]

@MaEtUgR - how is Cygwin updated? Could this be related to and issue with Python on Cygwin that got fixed?

[MaEtUgR]

@davids5 The toolchain can locally be updated. The version deployed in the installer is updated by generating a new installer through CI. It fetches the latest Cygwin packages here: https://github.com/PX4/windows-toolchain/blob/master/appveyor.yml#L21 But Cygwin is rather conservative and stable (vs bleeding edge). At least I didn't update the toolchain recently.

[stale]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.

[julianoes]

@MaEtUgR so this is fixed?

[MaEtUgR]

I don't think so but since I consider it a minor problem I'm not planning to look into this very soon.

[stale]

This issue has been automatically marked as stale because it has not had recent activity. Thank you for your contributions.