DTR/RTS reset feature currently broken when using Chrome browser on Linux/Mac

[basilhussain]

If you are experiencing failures with error messages of "Error occurred attempting to toggle DTR/RTS sequence for reset into bootloader" in the log, and are using a Chromium-based browser version 139.0.7258.66 on a POSIX-based platform (Linux, Mac, etc.), then unfortunately this is due to a browser bug.

This is not a bug in the Web ISP code, and will be resolved when the bug is fixed in the browser.

This bug does not affect Windows users.

[basilhussain]

A workaround is to start the browser with a command-line option of --disable-features=SerialSplitDtrAndRts. This will revert to the old behaviour and allow the DTR/RTS reset feature to work again.

[basilhussain]

The 139.0.7258.127 and 139.0.7258.128 versions of Chromium now by default revert to the previous behaviour, without having to resort to using the command-line option.

Users should ensure they have the latest browser version installed to avoid this bug.

[dhalbert]

@basilhussain Per https://issues.chromium.org/issues/437068905#comment13, the latest Chrome Dev and Canary are supposed to have the ioctl() fix, but when I try esptool-js with Canary, it still doesn't work (https://issues.chromium.org/issues/437068905#comment14). I think you're cc'd on all that, but your own testing would be great. Thanks.

[dhalbert]

@basilhussain On further testing I cannot reproduce, and enabling SerialSplitDtrAndRts now works with esptool-js. But it would obviously be good for you to test with your tool.

[basilhussain]

Everything works fine for me with Chrome Canary 141.0.7363.0. Seems to have SerialSplitDtrAndRts enabled by default; no command-line options required.

@dhalbert guess you had a PEBKAC issue. 😅