Hi, On 05/11/2014 11:53 AM, Siarhei Siamashka wrote: > It has been confirmed that a substantial percentage of cubieboard2 > and cubietruck users are having stability issues. These issues are > caused by having various voltages optimistically configured way too > low. Because each unit has its own tolerances, not everyone can > easily reproduce these problems. > > To address the issue, we take the updated settings from: > > https://github.com/cubieboard/cubie_configs/tree/09e511721697/sysconfig/linux > This repository is relevant because it is referenced from: > > http://docs.cubieboard.org/tutorials/ct1/development/compiling_latest_kernel_for_cubietruck_cubieboard3 > Please note that there is also a sunxi-boards repository fork at > https://github.com/cubieboard (with bad settings) and this makes > things more confusing than necessary. > > Signed-off-by: Siarhei Siamashka <[email protected]> > --- > sys_config/a20/cubieboard2.fex | 18 +++++++++--------- > sys_config/a20/cubietruck.fex | 16 ++++++++-------- > 2 files changed, 17 insertions(+), 17 deletions(-) > > diff --git a/sys_config/a20/cubieboard2.fex b/sys_config/a20/cubieboard2.fex > index 1436df8..c8c9c74 100644 > --- a/sys_config/a20/cubieboard2.fex > +++ b/sys_config/a20/cubieboard2.fex > @@ -1,14 +1,14 @@ > [product] > version = "100" > -machine = "cubieboard" > +machine = "cubieboard2" > > [platform] > eraseflag = 0 > > [target] > boot_clock = 912 > -dcdc2_vol = 1400 > -dcdc3_vol = 1250 > +dcdc2_vol = 1450
This makes no sense, since in the dvfs table there is: max_freq = 912000000 LV2_freq = 912000000 LV2_volt = 1425 S0 1.425 volt would make a lot more sense. Also Page 31 of A20+Datasheet+v1.0+20130227.pdf says that the MAX CPU and systemvoltage is 1425 volts. So what this patch effectively does is overvolt the CPU cores and base system. Now overvolting is a well know trick when doing overclocking, the question is do we really want to ship a config which overvolts by default? My first instinctive reaction is no we don't. But if this cures our stability issues, then I think it makes sense to do so, in this case u-boot should be changed to init the cpu voltage to 1.425 volt by default too. Note all these new settings significantly exceed the official allwinner settings / the settings found in any other a20 device fex file. If we want to make these changes, we should probably change this for all boards. Regards, Hans -- You received this message because you are subscribed to the Google Groups "linux-sunxi" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. For more options, visit https://groups.google.com/d/optout.
