Re: [PATCH] clk: meson: g12a: fix gp0 and hifi ranges

From: Neil Armstrong <narmstrong@baylibre.com>
To: Jerome Brunet <jbrunet@baylibre.com>
Cc: Kevin Hilman <khilman@baylibre.com>,
	linux-amlogic@lists.infradead.org, linux-clk@vger.kernel.org,
	linux-kernel@vger.kernel.org
Subject: Re: [PATCH] clk: meson: g12a: fix gp0 and hifi ranges
Date: Thu, 20 May 2021 16:02:40 +0200	[thread overview]
Message-ID: <df839588-1ff2-2d7f-4364-2b0d8942d6ef@baylibre.com> (raw)
In-Reply-To: <20210429090325.60970-1-jbrunet@baylibre.com>

On 29/04/2021 11:03, Jerome Brunet wrote:
> While some SoC samples are able to lock with a PLL factor of 55, others
> samples can't. ATM, a minimum of 60 appears to work on all the samples
> I have tried.
> 
> Even with 60, it sometimes takes a long time for the PLL to eventually
> lock. The documentation says that the minimum rate of these PLLs DCO
> should be 3GHz, a factor of 125. Let's use that to be on the safe side.
> 
> With factor range changed, the PLL seems to lock quickly (enough) so far.
> It is still unclear if the range was the only reason for the delay.
> 
> Fixes: 085a4ea93d54 ("clk: meson: g12a: add peripheral clock controller")
> Signed-off-by: Jerome Brunet <jbrunet@baylibre.com>
> ---
>  drivers/clk/meson/g12a.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/clk/meson/g12a.c b/drivers/clk/meson/g12a.c
> index b080359b4645..a805bac93c11 100644
> --- a/drivers/clk/meson/g12a.c
> +++ b/drivers/clk/meson/g12a.c
> @@ -1603,7 +1603,7 @@ static struct clk_regmap g12b_cpub_clk_trace = {
>  };
>  
>  static const struct pll_mult_range g12a_gp0_pll_mult_range = {
> -	.min = 55,
> +	.min = 125,
>  	.max = 255,
>  };
>  
> 

Sorry for bothering with the DSI stuff, I'll fix this when we are ready to upstream DSI support for G12A.

I had this patch for a while in my integration branches, so:
Acked-by: Neil Armstrong <narmstrong@baylibre.com>

Neil