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SubjectRe: [PATCH 0/3] ARM: OMAP5+: Support Duty Cycle Correction(DCC)
On 05/16/2014 01:45 PM, Nishanth Menon wrote:
> Hi,
>
> This patch series has been carried over in vendor kernel for quiet
> few years now.
>
> Unfortunately, it was very recently re-discovered and upstream kernel
> is noticed to be broken for OMAP5 1.5GHz - at least we are operating
> DPLL at frequency higher than what it was intended to be when CPUFreq
> is enabled. Thankfully, with nominal voltage(we dont use AVS yet in
> upstream for the mentioned platforms) and margins in trimming, we
> have so far not crashed - but I strongly suspect this might be some
> boundary case survival.
>
> Verified on the following impacted platforms using 3.15-rc4 based
> vendor kernel.
>
> Before:
> OMAP5432: http://slexy.org/view/s20cs0qQFg
> DRA72x: http://slexy.org/view/s2TXtSa6mH (refused to lock)
> DRA75x: http://slexy.org/view/s20AW8MU5c
> After:
> OMAP5432: http://slexy.org/view/s21iAfWxpu
> DRA72x: http://slexy.org/view/s2hwsvGLmC (locks properly)
> DRA75x: http://slexy.org/view/s21ehw8WQn
>
> Hopefully, we can get these into some kernel revision in some form.

Thanks, queued for 3.16/ti-clk-drv. Anybody on the delivery feel free to
yell if you got any complaints.

-Tero

>
> NOTE: Support for 4470(which is the only other platform requiring
> DCC) is not present in upstream kernel and there are no plans to
> support that SoC, even if it is added at a later point, support can be
> extended as needed.
>
> Series based on v3.15-rc5 tag.
> Also available on my tree:
> https://github.com/nmenon/linux-2.6-playground/
> branch: push/clock/dcc
>
> weblink: https://github.com/nmenon/linux-2.6-playground/commits/push/clock/dcc
>
> Verification:
> 3.15-rc4 based kernel - DRA75x-evm, 72x-evm, OMAP5uevm
> 3.15-rc5 - OMAP5uEVM(only one supporting 1.5GHz atm)
>
> Andrii Tseglytskyi (1):
> ARM: OMAP5+: dpll: support Duty Cycle Correction(DCC)
>
> Nishanth Menon (2):
> clk: dpll: support OMAP5 MPU DPLL that need special handling for
> higher frequencies
> ARM: dts: OMAP5/DRA7: use omap5-mpu-dpll-clock capable of dealing
> with higher frequencies
>
> .../devicetree/bindings/clock/ti/dpll.txt | 1 +
> arch/arm/boot/dts/dra7xx-clocks.dtsi | 2 +-
> arch/arm/boot/dts/omap54xx-clocks.dtsi | 2 +-
> arch/arm/mach-omap2/dpll3xxx.c | 9 +++++++++
> drivers/clk/ti/dpll.c | 21 ++++++++++++++++++++
> include/linux/clk/ti.h | 4 ++++
> 6 files changed, 37 insertions(+), 2 deletions(-)
>
> Regards,
> Nishanth Menon
>



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