[Sdhci-devel] sdhci problems with debug log

[Pierre Ossman]

On Tue, 15 Jan 2008 17:17:53 +0000
Simon Huggins <huggie at earth.li> wrote:

> 
> Ok.  If I use an HZ=1000 then it works.  I don't have CONFIG_NO_HZ
> (tickless kernel) enabled.
> 
> When I do use HZ=1000 I also get printed: mmc_detect_change(500) from
> the old debugging code I left in whereas before with HZ=250 it was 125.
> 

This is expected. The value you see in the dump is HZ / 2 (i.e. 0.5
seconds).

> I don't know if this is your bug or the scheduler's but given that my
> original post cited mmc_delay changes causing it perhaps it's still
> broken for other values of HZ.
> 

Since it is so uniformly broken, it's some kind of scheduler bug. And
I'm not much help there I'm afraid. You'll have to ask Ingo Molnar and
the other scheduler hackers for help at this point.

Rgds
-- 
     -- Pierre Ossman

  Linux kernel, MMC maintainer        http://www.kernel.org
  PulseAudio, core developer          http://pulseaudio.org
  rdesktop, core developer          http://www.rdesktop.org