Re: [PATCH tty 1/1] serial: 8250: Change console_msr_work to IRQ_WORK_LAZY

[Jon Hunter <jonathanh@nvidia.com>]

On 28/08/2026 17:06, Sebastian Andrzej Siewior wrote:
> On 2026-08-28 18:04:08 [+0206], John Ogness wrote:
>> For some platforms it is a problem to queue irq_work when entering
>> cpuidle states. Since irq_work is used for deferred MSR handling,
>> any atomic console printing when entering cpuidle states can lead
>> to the affected hardware hanging. Tegra20 and Tegra30 are examples
>> of such platforms. Avoiding raising the irq_work IRQ has shown to
>> circumvent the problem.
> 
> I would argue that this is done for the benefit of less interrupts since
> there no need to handle console_msr_work immediately. With the side
> effect that it might fix a bug that was not yet reported on Tegra[23]0.
> 
> Ideally the Tegra folks should figure out what exactly is broken instead
> of adding duct tape everywhere else.

Yes that would be ideal. Unfortunately these are old devices now and very
much in maintenance mode so getting to the bottom of this now is unlikely.
You may say then why don't we completely deprecate these, but then you
could argue the other way and say they have been working fine up until
now.

Jon

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