Hi, On 10/14/2014 11:25 PM, Siarhei Siamashka wrote: > On Mon, 13 Oct 2014 13:10:28 +0200 > Hans de Goede <[email protected]> wrote: > >> Hi, >> >> On 10/04/2014 07:53 AM, Siarhei Siamashka wrote: >>> When PLL5P is used as a parent clock for some of the peripherals, >>> the current code just selects some hardcoded divisors. This happens >>> to work, but only under assumption that the PLL5P clock speed is >>> somewhere between 360MHz and 480MHz (the typical DRAM clock speeds). >>> >>> However with some tweaks for the DRAM parameters, it is possible to >>> clock DRAM up to 600MHz and more on some devices: >>> >>> http://lists.denx.de/pipermail/u-boot/2014-July/183981.html >>> >>> And this introduces concerns about the hardcoded divisors in the >>> kernel, which may cause some peripherals to operate at abnormally >>> high clock speeds if the PLL5 clock speed is too fast (PLL5 is used >>> for clocking DRAM). >>> >>> Moreover, it makes sense to avoid pre-dividing PLL5P and make it run >>> even faster than DRAM. This provides better granularity of the clock >>> speed selection for MBUS, G2D and everything else that is using PLL5P >>> as the parent clock. but running PLL5P faster means that the hardcoded >>> divisors become even more inappropriate. >>> >>> This patch improves the clock divisors selection for G2D, ACE and >>> DEBE to insure that they can work correctly with any PLL5P clock >>> speed. >>> >>> Signed-off-by: Siarhei Siamashka <[email protected]> >> >> Looks good: >> >> Acked-by: Hans de Goede <[email protected]> >> >> Can we please get this merged, > > You know the rules. Every patch needs to be approved by at least one > person other than the submitter. > > Thanks for the review. Pushed to stage/sunxi-3.4 > >> I'm working on getting the sunxi-3.4 kernels to work with upstream >> u-boot, so that we can stop maintaining our own fork, >> and this is necessary for this. > > I hope we don't get in each other's way with this stuff.
I hope so too :) I'm actually more or less done now, I've just send out 2 sunxi-3.4 patches (which are quite similar to your 2, but for slightly different areas), which completes my sunxi-3.4 work. With these patches the 3.4 kernels will work on sun4i / sun5i with an unmodified upstream u-boot. Still I've decided to revert your PLL5 changes in upstream u-boot (for now) as I really want people to be able to run unmodified android kernels on the upstream u-boot. My main reason for this is that I want to take away any reasons people may have to keep using the linux-sunxi/u-boot-sunxi u-boot "fork", so that we can focus all u-boot work upstream. Besides the revert I've also been working on solving the A20 problem, I'm currently at ELCE, and I've been talking to various u-boot people about this, including Marc Zyngier, and we've come up with a solution which should be acceptable for upstream inclusion. See the 2 u-boot patches I'm about to send for details. I'll put you in the Cc of them. About the pll5 settings revert, if you disagree, please reply to the patch I'm about to send for this, as the proper venue to discuss that is the upstream u-boot list. 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.
