Re: [PATCH 2/6 v5] clk, highbank: Prevent glitches in non-bypassreset mode

From: Mike Turquette
Date: Tue Nov 27 2012 - 13:16:03 EST


On Tue, Nov 27, 2012 at 7:04 AM, Mark Langsdorf
<mark.langsdorf@xxxxxxxxxxx> wrote:
>
> The highbank clock will glitch with the current code if the
> clock rate is reset without relocking the PLL. Program the PLL
> correctly to prevent glitches.
>
> Signed-off-by: Mark Langsdorf <mark.langsdorf@xxxxxxxxxxx>
> Signed-off-by: Rob Herring <rob.herring@xxxxxxxxxxx>
> Cc: mturquette@xxxxxxxxxx

Acked-by: Mike Turquette <mturquette@xxxxxxxxxx>

Regards,
Mike

> ---
> Changes from v4
> None.
> Changes from v3
> Changelog text and patch name now correspond to the actual patch.
> was clk, highbank: remove non-bypass reset mode.
> Changes from v2
> None.
> Changes from v1:
> Removed erroneous reformating.
>
> drivers/clk/clk-highbank.c | 2 ++
> 1 file changed, 2 insertions(+)
>
> diff --git a/drivers/clk/clk-highbank.c b/drivers/clk/clk-highbank.c
> index 52fecad..3a0b723 100644
> --- a/drivers/clk/clk-highbank.c
> +++ b/drivers/clk/clk-highbank.c
> @@ -182,8 +182,10 @@ static int clk_pll_set_rate(struct clk_hw *hwclk, unsigned long rate,
> reg |= HB_PLL_EXT_ENA;
> reg &= ~HB_PLL_EXT_BYPASS;
> } else {
> + writel(reg | HB_PLL_EXT_BYPASS, hbclk->reg);
> reg &= ~HB_PLL_DIVQ_MASK;
> reg |= divq << HB_PLL_DIVQ_SHIFT;
> + writel(reg | HB_PLL_EXT_BYPASS, hbclk->reg);
> }
> writel(reg, hbclk->reg);
>
> --
> 1.7.11.7
>
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