apple-isp: firmware fails to start on t8122 (MacBook Air M3), camera never enumerates #630

Machine: MacBook Air 13" M3 2024 (Mac15,12, t8122)
OS: Fedora Asahi Remix 44 KDE, fully updated (dnf upgrade --refresh clean)
Install: asahi-installer 0.9.2, non-expert, all defaults

The internal camera never appears in userspace. cam -l
(libcamera 0.7.1) lists no cameras.

dmesg shows apple-isp probing and finding the sensor, then
failing to start the command processor:
apple-isp 2a4000000.isp: ISP firmware-compat: 14.7 (FW: 14.7)
apple-isp 2a4000000.isp: found sensor 558 DNM40610DHQ0WNMDZ on ch 0
apple-isp: ps: CISP_CMD_CH_CAMERA_CONFIG_GET: 0 through 5
apple-isp 2a4000000.isp: [isp_stop_command_processor] never received magic number from firmware
apple-isp 2a4000000.isp: apple-isp probe!

All six camera configs enumerate first, so the driver is
talking to the hardware. It only fails at the handshake.

This reproduces on every boot, including a clean boot right
after running sudo asahi-fwupdate. When an application tries
to open the camera, the same failure repeats with IO timeouts
and failed opcodes 0x0101, 0x0104 and 0x0021.

I raised this in #asahi:fedoraproject.org first. I was told
the camera is expected to work on M3, and that someone else
had seen the ISP firmware fail to start on this platform but
it was unclear whether it was fixed.

Note: the diagnose log contains an "unsupported firmware
version (14.7) on this platform (t8122)" warning and an audio
config warning. Both were confirmed in chat as false
positives, since asahi-diagnose has not been updated for M3.
This was a stock non-expert install.

Note: the input device Uniq field is redacted. Nothing
else in the log was modified.

asahi-diagnose-20260919-104444-redacted.txt