Messages in this thread |  | | | Date | Wed, 20 Aug 2008 22:37:15 -0700 | | From | "H. Peter Anvin" <> | | Subject | Re: [PATCH] i486 CR4 oops, no_console_suspend | |
David Fries wrote:
> On Tue, Aug 19, 2008 at 09:07:26AM -0700, H. Peter Anvin wrote:
>> Ingo Molnar wrote:
>>> i've had trouble no end with getting even kernel messages out to the
>>> serial console during critical phases of suspend/resume. (especially in
>>> combination with earlyprintk=ttyS0 - not surprisingly)
>>>
>>> Especially during resume the UART is initialized back to something
>>> really slow - 300 bauds or 9600 bauds. (depends on the chipset i guess)
>>> So even though it works, it will only worked reliably when i
>>> standardized all my baud settings to that very low setting.
>>>
>> Probably depends on the BIOS, actually; I suspect you end up with the
>> standard BIOS setting, which is *usually* 9600 bps.
>
> I have grub, the kernel, and a getty all set to 115200, for suspend,
> resume, or reboot it's always 115200. With grub there's no BIOS
> guessing, it sets it to a configured state.
>
Most likely it never gets reinitialized during resume. This is a bug,
obviously.
-hpa
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