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)Probably depends on the BIOS, actually; I suspect you end up with the standard BIOS setting, which is *usually* 9600 bps.
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.
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.