Kernel crash in stm32_usart DMA during runtime resume (vchan_tx_submit Oops) on STM32MP2 (Yocto 6.6)

[het49_]

Hello,

I am facing a kernel crash (Oops) on an STM32MP2 platform while using UART with DMA. The issue occurs during runtime power management resume.

Environment
Platform: STM32MP2 (custom board)
Kernel: 6.6.78 (OpenSTLinux - Yocto Scarthgap)
UART driver: stm32_usart
DMA: Enabled
Workqueue: pm_runtime_work

Observations:
Crash happens in DMA virtual channel submission
Triggered during runtime resume (PM)
Address dead000000000xxx suggests:
Use-after-free, or
Uninitialized / corrupted DMA descriptor

Are there any patches or recommended fixes for this scenario?

[Erwan SZYMANSKI]

Hello @het49_ ,
Could you please try the patch I shared in the following topic: https://community.st.com/t5/stm32-mpus-embedded-software-and/stm32mp257-unable-to-handle-kernel-paging-request-at-virtual/m-p/872261 ? 

Kind regards,
Erwan.