2021-07-13 19:57:15

by Oleksandr Suvorov

Subject: [PATCH] ARM: dts: colibri-imx6ull: limit SDIO clock to 25MHz

NXP and AzureWave don't recommend using SDIO bus mode 3.3V@50MHz due
to noise affecting the wireless throughput. Colibri iMX6ULL uses only
3.3V signaling for Wi-Fi module AW-CM276NF.

Limit the SDIO Clock on Colibri iMX6ULL to 25MHz.

Signed-off-by: Oleksandr Suvorov <[email protected]>
---

arch/arm/boot/dts/imx6ull-colibri-wifi.dtsi | 1 +
1 file changed, 1 insertion(+)

diff --git a/arch/arm/boot/dts/imx6ull-colibri-wifi.dtsi b/arch/arm/boot/dts/imx6ull-colibri-wifi.dtsi
index a0545431b3dc..9f1e38282bee 100644
--- a/arch/arm/boot/dts/imx6ull-colibri-wifi.dtsi
+++ b/arch/arm/boot/dts/imx6ull-colibri-wifi.dtsi
@@ -43,6 +43,7 @@ &usdhc2 {
assigned-clock-rates = <0>, <198000000>;
cap-power-off-card;
keep-power-in-suspend;
+ max-frequency = <25000000>;
mmc-pwrseq = <&wifi_pwrseq>;
no-1-8-v;
non-removable;
--
2.31.1

2021-07-13 20:11:59

by Fabio Estevam

Subject: Re: [PATCH] ARM: dts: colibri-imx6ull: limit SDIO clock to 25MHz

Hi Oleksandr,

On Tue, Jul 13, 2021 at 4:54 PM Oleksandr Suvorov
<[email protected]> wrote:
>
> NXP and AzureWave don't recommend using SDIO bus mode 3.3V@50MHz due
> to noise affecting the wireless throughput. Colibri iMX6ULL uses only
> 3.3V signaling for Wi-Fi module AW-CM276NF.
>
> Limit the SDIO Clock on Colibri iMX6ULL to 25MHz.

What about adding a Fixes tag so that it can go to the stable trees?

Reviewed-by: Fabio Estevam <[email protected]>

2021-07-13 20:26:54

by Oleksandr Suvorov

Subject: Re: [PATCH] ARM: dts: colibri-imx6ull: limit SDIO clock to 25MHz

Hi Fabio,
On Tue, Jul 13, 2021 at 11:10 PM Fabio Estevam <[email protected]> wrote:
>
> Hi Oleksandr,
>
> On Tue, Jul 13, 2021 at 4:54 PM Oleksandr Suvorov
> <[email protected]> wrote:
> >
> > NXP and AzureWave don't recommend using SDIO bus mode 3.3V@50MHz due
> > to noise affecting the wireless throughput. Colibri iMX6ULL uses only
> > 3.3V signaling for Wi-Fi module AW-CM276NF.
> >
> > Limit the SDIO Clock on Colibri iMX6ULL to 25MHz.
>
> What about adding a Fixes tag so that it can go to the stable trees?

Good point, thanks! I'll add in the 2nd version.
>
> Reviewed-by: Fabio Estevam <[email protected]>

Thanks for the review!

Best regards
Oleksandr Suvorov

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