Re: [PATCH v2 0/2] clk: sunxi: Fix APBS clock for Allwinner A80

From: Chen-Yu Tsai
Date: Fri Feb 12 2016 - 21:30:11 EST


Hi,

On Fri, Feb 12, 2016 at 5:31 PM, Chen-Yu Tsai <wens@xxxxxxxx> wrote:
> Hi everyone,
>
> This is v2 of the A80 APBS clock fixes series.
>
> When I did the A80 PRCM support, I failed to notice the A80's APBS clock
> was not the same as the A23's APB0 clock. The former is a zero-based
> divider, while the latter is a power-of-two divider. But the lowest 2
> dividers are the same.

It turns out that clk-sun8i-a23-apb0 was wrong. It's a zero-based divider,
not a power-of-two divider as the driver says. Thanks to Vishnu for pointing
it out. So NACK on this series.

I'll send a patch fixing this, but what should we do for old kernels?
I don't think backporting the CLK_OF_DECLARE changes is acceptable.
Maybe a stable patch based on the fix?

Sorry for the noise.

ChenYu

> The hardware defaults to the lowest setting, or a /1 divider. Since the
> child gates do not propagate clk_set_rate up, and no consumers here do
> clk_set_rate, this actually works.
>
> I realized my mistake while reviewing the A83T's PRCM patches. The A83T
> shares the same PRCM clocks as the A80.
>
> Maxime, since this was introduced in 4.5-rc1, please apply this series
> for 4.5 so we fix it before the release.
>
>
> Changes since v1:
>
> - Replace the CLK_OF_DECLARE version of sun8i-a23-apb0-clk with the
> A80 APBS version, instead of writing a new driver.
>
> Regards
> ChenYu
>
>
> Chen-Yu Tsai (2):
> clk: sunxi: Add support for A80 APBS clock
> ARM: dts: sun9i: Fix apbs clock compatible
>
> Documentation/devicetree/bindings/clock/sunxi.txt | 1 +
> arch/arm/boot/dts/sun9i-a80.dtsi | 2 +-
> drivers/clk/sunxi/clk-sun8i-apb0.c | 23 ++++++++---------------
> 3 files changed, 10 insertions(+), 16 deletions(-)
>
> --
> 2.7.0
>