On Thu, 19 Mar 2015 16:17:30 +0800 Chen-Yu Tsai <[email protected]> wrote:
> On Thu, Mar 19, 2015 at 2:57 PM, Siarhei Siamashka > <[email protected]> wrote: > > On Thu, 19 Mar 2015 10:39:32 +0800 > > Chen-Yu Tsai <[email protected]> wrote: > > > >> The Olimex A10-Lime is known to be unstable when running at 1008MHz. > >> > >> Signed-off-by: Chen-Yu Tsai <[email protected]> > >> --- > >> arch/arm/boot/dts/sun4i-a10-olinuxino-lime.dts | 14 ++++++++++++++ > >> 1 file changed, 14 insertions(+) > >> > >> diff --git a/arch/arm/boot/dts/sun4i-a10-olinuxino-lime.dts > >> b/arch/arm/boot/dts/sun4i-a10-olinuxino-lime.dts > >> index 31dc2f1c3870..16ecb8938e19 100644 > >> --- a/arch/arm/boot/dts/sun4i-a10-olinuxino-lime.dts > >> +++ b/arch/arm/boot/dts/sun4i-a10-olinuxino-lime.dts > >> @@ -74,6 +74,20 @@ > >> status = "okay"; > >> }; > >> > >> +&cpu0 { > >> + /* The A10-Lime is known to be unstable when running at 1008 MHz */ > >> + operating-points = < > >> + /* kHz uV */ > >> + 960000 1400000 > >> + 912000 1400000 > >> + 864000 1300000 > >> + 720000 1200000 > >> + 528000 1100000 > >> + 312000 1000000 > >> + 144000 900000 > >> + >; > >> +}; > >> + > >> &ehci0 { > >> status = "okay"; > >> }; > > > > Thanks for the patch. At least it should make my A10-OLinuXino-LIME > > working without obvious failures out of the box (the U-Boot is still > > another story though and there is a gap during boot up when the board > > is running with unreliable settings, but the probability of a failure > > is rather low). > > > > I should also mention that using 960MHz @1.4V does not fail, but it does > > not have any safety headroom either (the cyan 'sun4i_poorlime' line > > on the plot): > > > > > > http://people.freedesktop.org/~siamashka/files/20140512/sunxi-cpufreq-plot.png > > > > On the other hand, my board is on the worst part of the spectrum (many > > other a10-lime boards do not fail even at 1008MHz), so maybe having > > extra safety headroom is less necessary. > > > > An interesting question is whether the same problem may be reproducible > > on the Allwinner A10 devices other than A10-OLinuXino-LIME. My original > > problem report > > > > https://www.mail-archive.com/[email protected]/msg04343.html > > > > mentioned the A10-OLinuXino-LIME rev.A and introduced some sort of > > a bias by itself. At least I have seen people saying something like > > "my a10-lime revision is not rev.A, so it's none of my concern and > > I'm not going to bother running any tests". So far we have accumulated > > reports from 4 or 5 people having this reliability problem on their > > A10-OLinuXino-LIME (various revisions, not just rev.A), but not > > much from the other boards owners. > > > > Anyway, this particular patch is > > Tested-by: Siarhei Siamashka <[email protected]> > > Acked-by: Siarhei Siamashka <[email protected]> > > Good to hear it works. Did you test all the settings? You have nailed it. I was about to send the results of the full round of tests after running them a bit longer and revoke the initial Tested-by. Turns out that the 312MHz and 144MHz operating points fail to work reliable and tend to deadlock: Testing CPU 0 960 MHz ............................................................ OK 912 MHz ............................................................ OK 864 MHz ............................................................ OK 720 MHz ............................................................ OK 528 MHz ............................................................ OK 312 MHz ............................................................ OK 144 MHz Write failed: Broken pipe Testing CPU 0 960 MHz ............................................................ OK 912 MHz ............................................................ OK 864 MHz ............................................................ OK 720 MHz ............................................................ OK 528 MHz ............................................................ OK 312 MHz .................Write failed: Broken pipe > I copied the wrong settings, from sun5i-a13.dtsi instead of sun4i-a10.dtsi. I guess, this explains the problems at lower operating points. > I'll send a fixed version later. Thanks. -- Best regards, Siarhei Siamashka -- 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.
