Hi, Thanks for the patches. I've merged and pushed the 1st one.
The 2nd one esp. is a good find and a nice cleanup. It also seems to explain why we were getting various reports about instability on the cubieboard2, which ships with a dram clock of 480 where as it seems to be stable at 432, which exactly matches the threshold above which you say the timings become wrong. As Olliver already indicated we would like to do some more tests with the 2nd patch first, but eventually we definitely will want to merge it (assuming the testing goes well). I'm thinking that this means that we may be able to safely bump the dram clock on the cubietruck to 480, any opinion on this ? Regards, Hans On 03/26/2014 05:40 PM, Jens Kuske wrote: > I tried to start cleaning up the u-boot DRAM setup code for sunxi and > found a bug(?) that *could* be responsible for the low possible memory > frequencies on some boards like cubietruck. > > The patches don't raise any memory frequencies, but they could make it > possible to raise them. My cubietruck runs with 504MHz dram clock since > 24 hours, without any problems. But it also does this without the > patches, so this is no proof. > > I don't think these changes can break something, nonetheless they need > extensive testing on different boards. > > The first patch changes cubietruck dram parameters to provide correct > data for the second patch. I don't know what was the reason to set them > this way, but I didn't find any problems when setting them to the > technically correct values. > > The second patch does the real work. It is based on guesses, but > they fit very well, so I think they are the truth. > I don't know if this really was responsible for the low frequency or > any other memory problems, but it was obviously wrong, as explained in > the commit message. > > What do you think? > I'll try to continue clean up, but to not break anything I believe it > is better to do it in really small steps. > > > > Jens Kuske (2): > sunxi: dram: Adjust cubietruck dram chip width and density > sunxi: dram: Fix autorefresh timing setup > > arch/arm/cpu/armv7/sunxi/dram.c | 70 > ++++++++++++---------------------- > arch/arm/include/asm/arch-sunxi/dram.h | 4 ++ > board/sunxi/dram_cubietruck.c | 4 +- > 3 files changed, 30 insertions(+), 48 deletions(-) > -- 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.
