lkml.org 
[lkml]   [2014]   [Dec]   [17]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
From
SubjectRe: [PATCH 11/12] ARM: dts: add support for Vybrid running on Cortex-M4
Date
On Tuesday 16 December 2014 23:19:08 Stefan Agner wrote:
> On 2014-12-03 12:03, Arnd Bergmann wrote:
> > On Wednesday 03 December 2014 01:12:10 Stefan Agner wrote:

> Just started looking in that a bit deeper and some question arose:
> Afaik, earlycon need to be supported by the uart driver. The fsl_lpuart,
> which is used for Vybrid's uart, does not support earlycon yet. However,
> earlyprink already works (see ./arch/arm/include/debug/vf.S). I
> understand that earlycon has the advantage of being able to be used on
> multiplatform. But earlyprintk is working really early (e.g. before
> locating the FDT), and it proved helpful for me when I started working
> on that Cortex-M4 stuff. Should earlycon replace earlyprintk completely?

earlyprintk will stay around for debugging early boot problems, but
with working earlycon support, there should no longer be a reason to
enable it by default.

> Maybe, on Vybrid, since it would be a good platform for automated !MMU
> testing, it would be nice to have earlycon which can be enabled in any
> case and would provide output even something blows up quite early... But
> I guess I would add earlycon support as part of a new patchset and just
> drop earlyprintk here for now.

Yes, I think that would be good.

> > 64 hash table entries sounds extremely small, doesn't that impact
> > performance? If you have 50MB of actual RAM available, I don't think
> > you need that.
>
> Agreed. I copied that from EFM32 which is under much more memory
> pressure...

Ok.

Arnd


\
 
 \ /
  Last update: 2014-12-17 12:41    [W:2.588 / U:0.012 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site