Problem with nbcon console and amba-pl011 serial port
Ryo Takakura
ryotkkr98 at gmail.com
Tue Jun 3 02:03:13 PDT 2025
Hi!
On Tue, 3 Jun 2025 03:18:23 +0000, Michael Kelley wrote:
>The problem is timing dependent. In some cases, the "pr/ttyAMA0"
>thread is evidently able to get the message out before panic() calls
>pr_emerg(). In my case running as a guest on Hyper-V, the pl011 device
>in the guest VM is emulated by Hyper-V. Each pl011 register access
>traps to the hypervisor, which slows things down and probably makes
>the problem more likely. But from what I can see, the underlying
>race condition exists regardless.
I believe the issue is not amba-pl011 specific, so maybe John and Petr
better be Cced as well.
Sincerely,
Ryo Takakura
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