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Ricard Rosson a2b3cbe9bc drivers/usbdev: re-assert soft connect in cdcecm/cdcncm disconnect()
The USB device controller drivers invoke CLASS_DISCONNECT() on every
USB bus reset, and a bus reset is the first step of normal host
enumeration.  Every other class driver (cdcacm, usbmsc, rndis)
re-asserts DEV_CONNECT() at the end of its disconnect() handler so
that the device remains attached; cdcecm and cdcncm did not, so on
controllers that soft-disconnect around bus reset (e.g. rp2040, which
drops the pull-up in its bus-reset handler) a standalone CDC-ECM or
CDC-NCM device is left soft-disconnected by the first bus reset and
never enumerates on the host.

Mirror the cdcacm behavior and perform the soft connect in the
disconnect() methods, unless part of a composite device (composite.c
already re-connects in its own disconnect handler).

Fixes the standalone CDC-ECM case of issue #15880.

Validated on raspberrypi-pico (RP2040): with this change a standalone
CONFIG_NET_CDCECM device that previously never appeared on the host
enumerates via cdc_ether and pings with 0% loss.  cdcncm has the
identical defect and receives the identical fix.

Signed-off-by: Ricard Rosson <ricard@groundbits.com>
Co-authored-by: Xiang Xiao <xiaoxiang781216@gmail.com>
Assisted-by: Claude (Anthropic Claude Code)
2026-08-04 09:35:20 +08:00
.github !arch/stm32: move stm32l1 and finalize the directory split 2026-07-03 10:27:27 +08:00
arch drivers/input: partial fix of indistinguishable ASCII and special keycodes 2026-08-04 09:33:53 +08:00
audio tools: fix stale archive members surviving a Kconfig-driven CSRCS change 2026-08-04 00:36:32 +08:00
binfmt tools: fix stale archive members surviving a Kconfig-driven CSRCS change 2026-08-04 00:36:32 +08:00
boards tools: fix stale archive members surviving a Kconfig-driven CSRCS change 2026-08-04 00:36:32 +08:00
cmake cmake: Sanitize NAME for _main symbol generation 2026-08-03 20:59:22 +08:00
crypto tools: fix stale archive members surviving a Kconfig-driven CSRCS change 2026-08-04 00:36:32 +08:00
Documentation docs/raspberrypi-4b: Documentation about the SD card updated 2026-08-03 20:57:47 +08:00
drivers drivers/usbdev: re-assert soft connect in cdcecm/cdcncm disconnect() 2026-08-04 09:35:20 +08:00
dummy build: add initial cmake build system 2023-07-08 13:50:48 +08:00
fs tools: fix stale archive members surviving a Kconfig-driven CSRCS change 2026-08-04 00:36:32 +08:00
graphics tools: fix stale archive members surviving a Kconfig-driven CSRCS change 2026-08-04 00:36:32 +08:00
include drivers/input: partial fix of indistinguishable ASCII and special keycodes 2026-08-04 09:33:53 +08:00
libs tools: fix stale archive members surviving a Kconfig-driven CSRCS change 2026-08-04 00:36:32 +08:00
mm mm/ubsan: fix signed inline value decoding 2026-08-04 09:34:08 +08:00
net net/ipfilter: Reassemble IPv6 fragments before filtering 2026-08-04 09:35:06 +08:00
openamp tools: fix stale archive members surviving a Kconfig-driven CSRCS change 2026-08-04 00:36:32 +08:00
pass1 tools: fix stale archive members surviving a Kconfig-driven CSRCS change 2026-08-04 00:36:32 +08:00
sched sched/sched: Fix uninitialized sporadic params returned by nxsched_get_param() 2026-08-04 09:34:23 +08:00
syscall tools: fix stale archive members surviving a Kconfig-driven CSRCS change 2026-08-04 00:36:32 +08:00
tools tools: fix stale archive members surviving a Kconfig-driven CSRCS change 2026-08-04 00:36:32 +08:00
video tools: fix stale archive members surviving a Kconfig-driven CSRCS change 2026-08-04 00:36:32 +08:00
wireless tools: fix stale archive members surviving a Kconfig-driven CSRCS change 2026-08-04 00:36:32 +08:00
.asf.yaml github: master branch protection tune. 2025-05-07 18:37:13 -05:00
.codespell-ignore-lines !boards: Remove NSH_ARCHINIT and board_app_initialize 2026-05-02 18:36:46 +08:00
.codespellrc arch/sim: replace macOS C++ constructor runtime hack with post-link patch 2026-05-19 07:08:55 -03:00
.editorconfig .editorconfig: fix character encoding property specification 2025-11-28 19:12:13 +08:00
.gitignore git: Specify multiple build directories in .gitignore. 2026-05-20 03:06:58 +08:00
.gitmessage docs/contributing: Add a commit message template 2025-06-03 17:33:24 +08:00
.pre-commit-config.yaml pre-commit: enable codespell checks 2025-05-05 12:34:39 +08:00
.yamllint feat: add a GitHub action to lint the YAML files 2020-12-15 09:52:04 -06:00
AUTHORS AUTHORS: add Eren Terzioglu 2026-05-20 15:17:00 +08:00
CMakeLists.txt cmake: Do not link an executable to detect the compiler. 2026-08-03 22:21:10 +08:00
CONTRIBUTING.md docs: Fix typos, formatting, and numbering in README.md and CONTRIBUTING.md. 2026-03-23 12:05:24 +01:00
INVIOLABLES.md INVIOLABLES.md: Fix a simple alignment and change occurrences of Nuttx 2020-09-03 01:33:05 +08:00
Kconfig sched/misc/assert: Add CONFIG_SCHED_DUMP_TASKS and CONFIG_SCHED_DUMP_STACK 2026-07-04 13:29:32 -04:00
LICENSE !arch/stm32: move stm32l1 and finalize the directory split 2026-07-03 10:27:27 +08:00
Makefile !boards: enforce secure ROMFS passwd and TEA key setup 2026-07-06 12:04:07 -03:00
NOTICE Remove the double blank line from source files 2022-02-20 20:10:14 +01:00
README.md docs: Fix typos, formatting, and numbering in README.md and CONTRIBUTING.md. 2026-03-23 12:05:24 +01:00
ReleaseNotes Documentation: move ReleaseNotes 2023-09-26 20:41:00 +08:00

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Apache NuttX is a real-time operating system (RTOS) with an emphasis on standards compliance and small footprint. Scalable from 8-bit to 64-bit microcontroller environments, the primary governing standards in NuttX are POSIX and ANSI standards. Additional standard APIs from Unix and other common RTOSs (such as VxWorks) are adopted for functionality not available under these standards, or for functionality that is not appropriate for deeply-embedded environments (such as fork()).

For brevity, many parts of the documentation will refer to Apache NuttX as simply NuttX.

Getting Started

First time on NuttX? Read the Getting Started guide! If you don't have a board available, NuttX has its own simulator that you can run on terminal.

Documentation

You can find the current NuttX documentation on the Documentation Page.

Alternatively, you can build the documentation yourself by following the Documentation Build Instructions.

The old NuttX documentation is still available in the Apache wiki.

Supported Boards

NuttX supports a wide variety of platforms. See the full list on the Supported Platforms page.

Contributing

If you wish to contribute to the NuttX project, read the Contributing guidelines for information on Git usage, coding standard, workflow and the NuttX principles.

License

The code in this repository is under either the Apache 2 license, or a license compatible with the Apache 2 license. See the License Page for more information.