nuttx/drivers
Justin Hammond 8279a7e755 drivers/usbhost: Refuse to register the same class driver twice.
The registry is a singly linked list of static structures, so registering
one of them a second time does not add a second entry: it points that
entry's own link at itself, and the list stops having an end.

Nothing notices while every device that turns up matches something near
the head, because the search returns before it reaches the loop.  The
first device that matches nothing at all, meaning anything without a
class driver built in, walks the list to look for it and never comes back,
holding the registry lock.  On a multiprocessor the rest of the system
follows it down: every other processor that touches the registry spins,
and on the one measured here that included the console, so a board with a
USB keyboard and no keyboard driver came up and then answered nothing.

Registering twice is easy to do by accident.  drivers_initialize() calls
usbhost_drivers_initialize(), which registers every class the
configuration selected, and board code that also registers one, which
many boards do, gets a second call for free.

So look before linking, and treat a repeat registration as the no-op the
caller expected it to be.

Assisted-by: Claude:claude-opus-5
Signed-off-by: Justin Hammond <justin@dynam.ac>
2026-08-08 14:55:34 -03:00
..
1wire drivers/efuse/efuse: Drivers Registered With World Write Permissions(Part 1) 2026-07-13 12:08:01 +02:00
aie drivers/efuse/efuse: Drivers Registered With World Write Permissions(Part 1) 2026-07-13 12:08:01 +02:00
analog drivers/analog: add MCP445X potentiometer support 2026-08-08 18:37:08 +08:00
audio drivers/efuse/efuse: Drivers Registered With World Write Permissions(Part 1) 2026-07-13 12:08:01 +02:00
bch drivers/efuse/efuse: Drivers Registered With World Write Permissions(Part 1) 2026-07-13 12:08:01 +02:00
can drivers/efuse/efuse: Drivers Registered With World Write Permissions(Part 1) 2026-07-13 12:08:01 +02:00
clk !include/fcntl.h: align open flags with Linux values 2026-06-30 13:43:44 +08:00
contactless drivers/contactless: fix uninitialized uid leak in mfrc522_read 2026-07-13 19:50:57 +08:00
coresight drivers/: Multiple Drivers Are Registered With World Writable - Part 2 2026-07-15 15:27:28 +08:00
crypto drivers/efuse/efuse: Drivers Registered With World Write Permissions(Part 1) 2026-07-13 12:08:01 +02:00
devicetree include/debug.h: Move to include/nuttx/debug.h 2026-04-07 07:50:06 -03:00
dma drivers: migrate to SPDX identifier 2024-11-06 18:02:25 +08:00
dummy drivers: migrate to SPDX identifier 2024-11-06 18:02:25 +08:00
eeprom drivers/eeprom: add 24CW160 support 2026-08-06 12:39:36 +02:00
efuse drivers/efuse/efuse: Drivers Registered With World Write Permissions(Part 1) 2026-07-13 12:08:01 +02:00
i2c drivers/efuse/efuse: Drivers Registered With World Write Permissions(Part 1) 2026-07-13 12:08:01 +02:00
i2s drivers/efuse/efuse: Drivers Registered With World Write Permissions(Part 1) 2026-07-13 12:08:01 +02:00
i3c drivers/: Multiple Drivers Are Registered With World Writable - Part 2 2026-07-15 15:27:28 +08:00
input drivers/input: support ST7123 touchscreen controller 2026-08-06 12:42:15 +02:00
ioexpander gpio: Fix GPIO expanders warnings 2026-08-01 11:15:11 +08:00
ipcc drivers/: Multiple Drivers Are Registered With World Writable - Part 2 2026-07-15 15:27:28 +08:00
lcd drivers/: Multiple Drivers Are Registered With World Writable - Part 2 2026-07-15 15:27:28 +08:00
leds drivers/: Multiple Drivers Are Registered With World Writable - Part 2 2026-07-15 15:27:28 +08:00
loop drivers/: Multiple Drivers Are Registered With World Writable - Part 2 2026-07-15 15:27:28 +08:00
math drivers/: Multiple Drivers Are Registered With World Writable - Part 2 2026-07-15 15:27:28 +08:00
misc libs/libc: Fix divide-by-zero in stat() with large filesystem block sizes 2026-07-16 23:37:22 +08:00
mmcsd drivers/mmcsd/mmcsd_sdio.c: Fix finfo print modifier 2026-08-03 23:18:48 +08:00
modem drivers/: Multiple Drivers Are Registered With World Writable - Part 2 2026-07-15 15:27:28 +08:00
motor drivers/: Multiple Drivers Are Registered With World Writable - Part 2 2026-07-15 15:27:28 +08:00
mtd libs/libc: Fix divide-by-zero in stat() with large filesystem block sizes 2026-07-16 23:37:22 +08:00
net drivers/: Multiple Drivers Are Registered With World Writable - Part 2 2026-07-15 15:27:28 +08:00
note drivers/: Multiple Drivers Are Registered With World Writable - Part 2 2026-07-15 15:27:28 +08:00
pci drivers/: Multiple Drivers Are Registered With World Writable - Part 2 2026-07-15 15:27:28 +08:00
pinctrl drivers/: Multiple Drivers Are Registered With World Writable - Part 2 2026-07-15 15:27:28 +08:00
pipes drivers/: Multiple Drivers Are Registered With World Writable Part 3 2026-07-16 09:49:07 -03:00
power drivers/: Multiple Drivers Are Registered With World Writable - Part 2 2026-07-15 15:27:28 +08:00
rc drivers/: Multiple Drivers Are Registered With World Writable - Part 2 2026-07-15 15:27:28 +08:00
regmap include/debug.h: Move to include/nuttx/debug.h 2026-04-07 07:50:06 -03:00
reset include/debug.h: Move to include/nuttx/debug.h 2026-04-07 07:50:06 -03:00
rf drivers/: Multiple Drivers Are Registered With World Writable - Part 2 2026-07-15 15:27:28 +08:00
rpmsg drivers/: Multiple Drivers Are Registered With World Writable - Part 2 2026-07-15 15:27:28 +08:00
rptun drivers/: Multiple Drivers Are Registered With World Writable - Part 2 2026-07-15 15:27:28 +08:00
segger drivers/segger: Download systemview from NuttX Mirror Repo 2026-06-03 19:19:24 +08:00
sensors drivers/sensors/sensor: pace POLLIN at the requested interval 2026-08-05 12:50:12 +02:00
serial drivers/serial: Modify serial/pty to allow NSH/Telnet line edit 2026-07-22 22:07:18 +08:00
spi drivers/spi/ice40: fix operator precedence in final clock cycle count 2026-07-20 17:05:01 +08:00
syslog drivers/syslog: fix syslog_write() returning -EIO on every write 2026-07-29 07:57:29 +02:00
thermal include/debug.h: Move to include/nuttx/debug.h 2026-04-07 07:50:06 -03:00
timers WDOG: Output status on read 2026-08-02 00:38:05 +08:00
usbdev drivers/usbdev/cdcacm: fix self-deadlock in cdcuart_txempty() 2026-08-07 19:11:27 -04:00
usbhost drivers/usbhost: Refuse to register the same class driver twice. 2026-08-08 14:55:34 -03:00
usbmisc drivers/: Multiple Drivers Are Registered With World Writable - Part 2 2026-07-15 15:27:28 +08:00
usbmonitor include/debug.h: Move to include/nuttx/debug.h 2026-04-07 07:50:06 -03:00
usrsock drivers/: Multiple Drivers Are Registered With World Writable - Part 2 2026-07-15 15:27:28 +08:00
vhost include/debug.h: Move to include/nuttx/debug.h 2026-04-07 07:50:06 -03:00
video drivers/video: zero message on MIPI DSI driver 2026-07-24 20:57:57 -03:00
virtio drivers/input: partial fix of indistinguishable ASCII and special keycodes 2026-07-29 22:51:15 -03:00
wireless wireless/lpwan/sx127x: fix the frequency step, the band and the LoRa only build 2026-08-06 13:01:39 -03:00
.gitignore
CMakeLists.txt drivers: migrate to SPDX identifier 2024-11-06 18:02:25 +08:00
drivers_initialize.c serial/uart_rpmsg: add _raw version of driver 2026-02-23 09:19:57 -03:00
Kconfig espressif/rmt: replace rmtchar with arch-specific lirc adapter 2026-04-04 11:18:32 -03:00
Makefile tools: fix stale archive members surviving a Kconfig-driven CSRCS change 2026-07-28 21:26:03 -03:00