How to actually set PICO_RP2040_USB_DEVICE_UFRAME_FIX=0?

[czietz]

The SDK 1.5.0 release notes mention the following new variable:

Defaulted new PICO_RP2040_USB_DEVICE_UFRAME_FIX variable to 1 as a workaround for errata RP2040-E15. This sets the default value for TinyUSB's dcd_rp2040 driver's TUD_OPT_RP2040_USB_DEVICE_UFRAME_FIX flag. This fix is required for correctness, but comes at the cost of some performance, so applications that won't ever be plugged into a Pi 4 or Pi 400 can optionally disable this by setting the value to 0.

However: How do I actually set PICO_RP2040_USB_DEVICE_UFRAME_FIX to 0? I would have expected to be able to add it to my CMakeLists.txt like other configuration parameters:

target_compile_definitions(my_project_name PRIVATE
PICO_RP2040_USB_DEVICE_UFRAME_FIX=0
)

However that results in a warning during the build process:

<command-line>: warning: "PICO_RP2040_USB_DEVICE_UFRAME_FIX" redefined
<command-line>: note: this is the location of the previous definition

... and checking the command-line shows that my project is still built with PICO_RP2040_USB_DEVICE_UFRAME_FIX=1.

Sadly, the SDK 1.5.0 documentation is (still?) missing, so I there isn't much documentation but the release notes.

PS: Also, the erratum RP2040-E15 is missing from the current RP2040 data sheet. Where I can find its description? PPS: Good to see that my humble example apparently was used as part of the test case for the E15 erratum: https://github.com/P33M/rp2040-e15-testcase/commit/2707219c2a28fd7f601448bba68d53261b13a1b0

[kilograham]

you have the right idea, but yes this is a bug.

for now use TUD_OPT_RP2040_USB_DEVICE_UFRAME_FIX=0 instead (either via target_compile_definitions or in your tusb_config.h`

[czietz]

Thank you. I can confirm that setting TUD_OPT_RP2040_USB_DEVICE_UFRAME_FIX=0 via target_compile_definitions has the intended effect of disabling the workaround for erratum E15.

[kilograham]

i have updated the release notes

[kilograham]

changed to "documentation" as the workaround is actually the correct thing to do

[lurch]

@kilograham AFAICT https://github.com/raspberrypi/pico-sdk/releases/tag/1.5.0 and Appendix F (SDK 1.5.0. Release Notes) of https://datasheets.raspberrypi.com/pico/raspberry-pi-pico-c-sdk.pdf and Appendix B (RP2040-E15) of https://datasheets.raspberrypi.com/rp2040/rp2040-datasheet.pdf are all describing using TUD_OPT_RP2040_USB_DEVICE_UFRAME_FIX - what other documentation updates are needed to fix this? (or are the ducks all already in a row? :duck: )

[lurch]

@P33M Are there any other changes needed here?

[P33M]

None?