Ticwatch C2+ (mobvoi-skipjack)

Features
Flashing	Works
USB Networking	Works
Internal storage
SD card
Battery
Screen	Partial
Touchscreen	Works
Multimedia
3D Acceleration
Audio
Camera
Camera Flash
IR TX
Connectivity
WiFi	Works
Bluetooth
GPS	Broken
NFC
Modem
Calls
SMS
Mobile data
Miscellaneous
FDE
USB OTG
HDMI/DP
Sensors
Accelerometer
Magnetometer
Ambient Light
Proximity
Hall Effect
Haptics
Barometer

Mobvoi Ticwatch C2+
	; Ticwatch C2+ running XFCE4
Manufacturer	Mobvoi
Name	Ticwatch C2+
Codename	mobvoi-skipjack
Released	2018
Type	watch
Hardware
Chipset	Qualcomm Snapdragon 210 (MSM8909)
CPU	Quad-core 1.1 GHz Cortex-A7
GPU	Adreno 304
Display	360x360 AMOLED
Storage	4 GB
Memory	1 GB
Architecture	armv7
Software
Original software	Wear OS
Original version	9
postmarketOS
Category	testing
Pre-built images	no

Contributors

ptrcnull

Users owning this device

How to enter flash mode

The watch supports flashing with fastboot. You can enter fastboot with adb reboot bootloader, or by rebooting and tapping the screen with two fingers (see video here).

Installation

WARNING: Doing this will delete ALL your data on the device, so backup all your data before continuing!

Before flashing postmarketOS you have to unlock your bootloader. To do so, you can run this command while in fastboot:

fastboot oem unlock

Follow the general installation guide with vendor mobvoi and codename skipjack, return here when told to (at the "installation and flashing section").

Now run the following, pick a password when prompted.

pmbootstrap install

Reboot back into fastboot (explained above).

pmbootstrap flasher flash_rootfs
pmbootstrap flasher flash_kernel

Reboot and you're good to go!

Broken stuff

Screen

For an unknown reason, msm_iommu_secure_fault_handler_v2 fails to get register dump after boot and the screen stays black. After disabling and re-enabling the display via following commands:

# echo 4 > /sys/class/graphics/fb0/blank
# echo 0 > /sys/class/graphics/fb0/blank

both IOMMU and the screen start working.

Modem/GPS

Device reboots after running msm-modem-downstream with following messages in kernel log:

[  148.027006] pil-q6v5-mss 4080000.qcom,mss: modem: Brought out of reset
[  148.078600] pil-q6v5-mss 4080000.qcom,mss: modem: Power/Clock ready interrupt received
[  148.078715] pil-q6v5-mss 4080000.qcom,mss: Subsystem error monitoring/handling services are up
[  148.079324] M-Notify: General: 7
[  148.126088] msm8952-asoc-wcd 7702000.sound: default codec configured
[  148.148391] msm8952-asoc-wcd 7702000.sound: ASoC: CODEC DAI cajon_vifeedback not registered
[  148.148744] msm8952-asoc-wcd 7702000.sound: snd_soc_register_card failed (-517)
[  148.486750] Fatal error on the modem.
[  148.486839] modem subsystem failure reason: fs_rmts_pm.c:855:[5, 6] rmts_read_iovec failed.
[  148.486900] subsys-restart: subsystem_restart_dev(): Restart sequence requested for modem, restart_level = SYSTEM.
[  148.489077] M-Notify: General: 8

No workaround found yet.