On 03/30/2017 09:36 PM, Paul Mackerras wrote:
> On Wed, Mar 22, 2017 at 04:27:50PM -0300, Guilherme G. Piccoli wrote:
>> The xmon parameter nobt was added long time ago, by commit 26c8af5f01df
>> ("[POWERPC] print backtrace when entering xmon"). The problem that time
>> was that during a crash in a machine with USB keyboard, xmon wouldn't
>> respond to commands from the keyboard, so printing the backtrace wouldn't
>> be possible.
>>
>> Idea then was to show automatically the backtrace on xmon crash for the
>> first time it's invoked (if it recovers, next time xmon won't show
>> backtrace automatically). The nobt parameter was added _only_ to prevent
>> this automatic trace show. Seems long time ago USB keyboards didn't work
>> that well!
>
> Xmon still can't use a USB keyboard. It's not a question of how well
> USB keyboards work, it's that having a non-interrupt-driven USB stack
> with (at least) an OHCI host controller driver and a keyboard driver
> in xmon is impractical.
That's nice to know Paul, thank you. Fortunately, we kept the automatic
trace showing feature!
Seems my commit message was unfortunate/wrong in this aspect, though.
@mpe, if you wanna change, feel free. Although it's not essential...
Cheers,
Guilherme
>
> Paul.
>
