2024-03-10 13:22:47

by Frank Oltmanns

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

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 <[email protected]>
Closes: https://groups.google.com/g/linux-sunxi/c/Rh-Uqqa66bw
Tested-by: Diego Roversi <[email protected]>
Cc: [email protected]
Reviewed-by: Maxime Ripard <[email protected]>
Signed-off-by: Frank Oltmanns <[email protected]>
---
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,
},
};


--
2.44.0

2024-03-13 19:07:38

by Jernej Škrabec

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

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 <[email protected]>
> Closes: https://groups.google.com/g/linux-sunxi/c/Rh-Uqqa66bw
> Tested-by: Diego Roversi <[email protected]>
> Cc: [email protected]
> Reviewed-by: Maxime Ripard <[email protected]>
> Signed-off-by: Frank Oltmanns <[email protected]>

Reviewed-by: Jernej Skrabec <[email protected]>

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,
> },
> };
>
>
>