[PATCH 3/4] mx25: fix time accounting

[Sascha Hauer]

Baruch,

On Mon, Jan 25, 2010 at 12:58:21PM +0200, Baruch Siach wrote:
> The gpt_clk rate function doesn't consider the PER divider. This causes a
> significant drift in time accounting. Fix this by introducing the correct rate
> calculation function.

Should have tested this one. In fact with this patch applied my clock
goes wrong.

The i.MX Timer code makes sure the gpt clock is sourced from the ipg
clock (GPTCR[6:8] = 1), so the behaviour should be correct the way it
was before this patch. Any idea why it was wrong on your hardware? Have
you changed the GPTCR bits?

Sascha

> 
> Signed-off-by: Baruch Siach <baruch at tkos.co.il>
> ---
>  arch/arm/mach-mx25/clock.c |    7 ++++++-
>  1 files changed, 6 insertions(+), 1 deletions(-)
> 
> diff --git a/arch/arm/mach-mx25/clock.c b/arch/arm/mach-mx25/clock.c
> index 08aaa38..c003ac4 100644
> --- a/arch/arm/mach-mx25/clock.c
> +++ b/arch/arm/mach-mx25/clock.c
> @@ -119,6 +119,11 @@ static unsigned long get_rate_nfc(struct clk *clk)
>  	return get_rate_per(8);
>  }
>  
> +static unsigned long get_rate_gpt(struct clk *clk)
> +{
> +	return get_rate_per(5);
> +}
> +
>  static unsigned long get_rate_otg(struct clk *clk)
>  {
>  	return 48000000; /* FIXME */
> @@ -156,7 +161,7 @@ static void clk_cgcr_disable(struct clk *clk)
>  		.secondary	= s,			\
>  	}
>  
> -DEFINE_CLOCK(gpt_clk,    0, CCM_CGCR0,  5, get_rate_ipg, NULL, NULL);
> +DEFINE_CLOCK(gpt_clk,    0, CCM_CGCR0,  5, get_rate_gpt, NULL, NULL);
>  DEFINE_CLOCK(uart_per_clk, 0, CCM_CGCR0, 15, get_rate_uart, NULL, NULL);
>  DEFINE_CLOCK(cspi1_clk,  0, CCM_CGCR1,  5, get_rate_ipg, NULL, NULL);
>  DEFINE_CLOCK(cspi2_clk,  0, CCM_CGCR1,  6, get_rate_ipg, NULL, NULL);
> -- 
> 1.6.5
> 
> 

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