[LAU] debian realtime kernel config 2.6.25.8.rt7

[David Baron]

On Monday 14 July 2008 20:20:41 Emanuel Rumpf wrote:
> 2008/7/14 David Baron <d_baron at 012.net.il>:
> >> you should then have a device
> >>   /dev/rtc0
> >
> > I have /dev/rtc from previous
>
> that's the old interface
> it's incompatible, deactivate it. look at my config!
>   ( zcat config.gz | grep -i rtc )
> see src/Documentation/rtc.txt for more info
>
> # CONFIG_RTC is not set
> # CONFIG_GEN_RTC is not set
> # CONFIG_HPET_RTC_IRQ is not set
It is not compatible with what?
Here is ~$ lsmod | grep rtc
snd_rtctimer            3616  0
rtc_cmos               10848  0
rtc_core               19632  1 rtc_cmos
rtc_lib                 3200  1 rtc_core
rtc                    14620  1 snd_rtctimer

The "old" rtc is used by snd_rtctimer so that needs also to be replaced if 
CONFIG_RTC will not be used. You may want the HPET in place of all of this?


>
> >> then change the max-user-frequency of rtc (default is only 64):
> >>   echo 2048 > /sys/class/rtc/rtc0/max_user_freq
> >
> > I have this set to 1024 (kernel hz?) in /etc/sysctl.conf.
>
> 1024 is ok too.
> for the new interface however, there doesn't seem to be a sysctl
> option anymore/yet and one has to set it manually.

Most everything seems to do sysctl. One can set it manually to see how it 
works out. If it is OK, it gets put in the sysctl so one need not manually set 
it again.

> > One caveat is that hal kicks out all the dma and 32-bit disk
> > accesses but they can be immediately set back so I put that in my startup
> > stuff as well.
>
> how do you set it up?
hdparm
> can/should that be done with any drive?
That gets done up front, hal bawks for some reason when starting. So for now, 
I hdparm again.
> any conditions?
I do not know why.