Re: [PATCH v4 2/5] clk: sunxi-ng: a64: Set minimum and maximum rate for PLL-MIPI

[Jernej Škrabec]

Dne nedelja, 10. marec 2024 ob 14:21:12 CET je Frank Oltmanns napisal(a):
> When the Allwinner A64's TCON0 searches the ideal rate for the connected
> panel, it may happen that it requests a rate from its parent PLL-MIPI
> which PLL-MIPI does not support.
> 
> This happens for example on the Olimex TERES-I laptop where TCON0
> requests PLL-MIPI to change to a rate of several GHz which causes the
> panel to stay blank. It also happens on the pinephone where a rate of
> less than 500 MHz is requested which causes instabilities on some
> phones.
> 
> Set the minimum and maximum rate of Allwinner A64's PLL-MIPI according
> to the Allwinner User Manual.
> 
> Fixes: ca1170b69968 ("clk: sunxi-ng: a64: force select PLL_MIPI in TCON0 mux")
> Reported-by: Diego Roversi <diegor@xxxxxxxxxx>
> Closes: https://groups.google.com/g/linux-sunxi/c/Rh-Uqqa66bw
> Tested-by: Diego Roversi <diegor@xxxxxxxxxx>
> Cc: stable@xxxxxxxxxxxxxxx
> Reviewed-by: Maxime Ripard <mripard@xxxxxxxxxx>
> Signed-off-by: Frank Oltmanns <frank@xxxxxxxxxxxx>

Reviewed-by: Jernej Skrabec <jernej.skrabec@xxxxxxxxx>

Best regards,
Jernej

> ---
>  drivers/clk/sunxi-ng/ccu-sun50i-a64.c | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/drivers/clk/sunxi-ng/ccu-sun50i-a64.c b/drivers/clk/sunxi-ng/ccu-sun50i-a64.c
> index 8951ffc14ff5..6a4b2b9ef30a 100644
> --- a/drivers/clk/sunxi-ng/ccu-sun50i-a64.c
> +++ b/drivers/clk/sunxi-ng/ccu-sun50i-a64.c
> @@ -182,6 +182,8 @@ static struct ccu_nkm pll_mipi_clk = {
>  					      &ccu_nkm_ops,
>  					      CLK_SET_RATE_UNGATE | CLK_SET_RATE_PARENT),
>  		.features	= CCU_FEATURE_CLOSEST_RATE,
> +		.min_rate	= 500000000,
> +		.max_rate	= 1400000000,
>  	},
>  };
>  
> 
>