svn commit: r259748 - releng/10.0/sys/arm/at91

[Warner Losh]

On Dec 22, 2013, at 3:47 PM, John-Mark Gurney wrote:

> Warner Losh wrote this message on Sun, Dec 22, 2013 at 22:31 +0000:
>>  The real fix is to use cngrab/cnungrab function pointers to disable
>>  RXRDY interrupts while grabbed. However, that touches the MI uart
>>  code, so was disallowed for 10.0 due to the lateness of the hour this
>>  fix was proposed. It works for mountroot, the most common atmel kernel
>>  prompt use cases, but wouldn't work for GELI since it prompts later in
>>  the boot process.
> 
> Hmmm, good point about geli, there have been complaints that the geli
> prompt gets garbled by other output (and I'm anoyed by it too)...
> 
> Can we solve this w/ grab?  How would the console code know the other
> writers don't have the console grabed?  Maybe by thread?

cngrab/cnungrab was meant to toggle between userland and kernel use of the console for input in rare cases. Contention doesn't seem to be covered at all, but could be...

Warner