Re: Problem with nbcon console and amba-pl011 serial port
From: Ryo Takakura <hidden>
Date: 2025-06-03 09:03:20
Also in:
linux-serial, lkml
From: Ryo Takakura <hidden>
Date: 2025-06-03 09:03:20
Also in:
linux-serial, lkml
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