On 05/08/2015 03:24 PM, Felipe Balbi wrote: > On Fri, May 08, 2015 at 03:12:27PM -0500, Nishanth Menon wrote: >> On 05/08/2015 03:09 PM, Nishanth Menon wrote: >>> On 05/08/2015 02:57 PM, Felipe Balbi wrote: >>>> By adding operating points, cpufreq-dt has a >>>> chance of running and doing something useful. >>>> >>>> Signed-off-by: Felipe Balbi <balbi@xxxxxx> >>>> --- >>>> arch/arm/boot/dts/am4372.dtsi | 9 +++++++++ >>>> 1 file changed, 9 insertions(+) >>>> >>>> diff --git a/arch/arm/boot/dts/am4372.dtsi b/arch/arm/boot/dts/am4372.dtsi >>>> index c80a3e233792..ea1db20f64fc 100644 >>>> --- a/arch/arm/boot/dts/am4372.dtsi >>>> +++ b/arch/arm/boot/dts/am4372.dtsi >>>> @@ -38,6 +38,15 @@ >>>> clocks = <&dpll_mpu_ck>; >>>> clock-names = "cpu"; >>>> >>>> + operating-points = < >>>> + /* kHz uV */ >>>> + 1000000 1325000 /* OPP_NITRO */ >>>> + 800000 1260000 /* OPP_TURBO */ >>>> + 720000 1200000 /* OPP_120 */ >>>> + 600000 1100000 /* OPP_100 */ >>>> + 300000 950000 /* OPP_50 */ >>>> + >; >>>> + >>>> clock-latency = <300000>; /* From omap-cpufreq driver */ >>>> }; >>>> }; >>>> >>> which of these OPPs need AVS? which of these are dependent on Efuse bit >>> dependent? >>> >> >> >> You can use >> http://git.ti.com/ti-linux-kernel/ti-linux-kernel/blobs/ti-linux-3.14.y/arch/arm/mach-omap2/opp43xx_data.c >> for reference. > > heh, why isn't that upstream yet ? Seems to be ready already. The point we have tried in the past[1] - unfortunately that was just bandaid since the existing OPP device tree bindings have very limiting behavior across multiple SoCs.This was one of the reasons why we stopped adding more OPPs, since we are hoping to see the new bindings[2] which is under discussion settle down and help enable support for cases like that we have on TI SoCs, iMX SoCs etc. > is that as of now, u-boot will set maximum OPP it can find and, for > AM437x, that will be 800MHz or 1GHz depending on your board. 1GHz might > not be supported in all SoCs and letting that be used all the time is > likely going to reduce silicon lifetime. > At least allowing ondemand governor run, we will be mostly running at > 300MHz and only jump to "invalid" OPPs under load which, granted, is > still not perfect, but better than running at 1GHz all the time, don't > you agree ? The fix for this should ideally be in u-boot - we are trying not to introduce dts changes in the hopes that the new proposed bindings that Viresh has on discussion comes to conclusion and help introduce new dtb support with proper SoC description. allowing an SoC to enter an invalid OPP is broken by design. we must attempt to curb it. unfortunately, we already do have a broken implementation for AM335x, DRA7 in place which went with the assumption that we will be able to do modifiers on top of existing dt description and the hopes that [1] will eventually get upstream. But, as is clear now, [1] has no future path in upstream kernel. following the same broken path for newer SoC definitions will probably very short sighted by us. in my opinion, doing a temporary hack in upstream kernel is not an elegant approach. I suggest helping review and approving Viresh's new bindings so that we have a longer term solution is more the way to do this. Just my 2 cents. Thanks once again for identifying the urgent need for helping Viresh's series along - will be great if folks could help review and approve his series to get them upstream and help all of us ARM SoC variations along. [1] http://comments.gmane.org/gmane.linux.ports.arm.kernel/309466 [2] http://marc.info/?l=devicetree&m=143039569104090&w=2 -- Regards, Nishanth Menon -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
