Re: [PATCH v3 1/8] arm64: dts: ti: k3-am62x-sk-common: Update main-i2c1 frequency

From: Nishanth Menon
Date: Sun Jul 30 2023 - 12:31:30 EST


On 23:04-20230728, Aradhya Bhatia wrote:
> The Display Data Channel (DDC) transactions between an HDMI transmitter
> (SIL9022A in this case) and an HDMI monitor, occur at a maximum of
> 100KHz. That's the maximum supported frequency within DDC standards.
>
> While the SIL9022A can transact with the core at 400KHz, it needs to
> drop the frequency to 100KHz when communicating with the monitor,
> otherwise, the i2c controller times out and shows warning like this.
>
> [ 985.773431] omap_i2c 20010000.i2c: controller timed out
>
> That feature, however, has not been enabled in the SIL9022 driver.
>
> Since, dropping the frequency doesn't affect any other devices on the
> bus, drop the main-i2c1 frequency from 400KHz to 100KHz.
>
> Signed-off-by: Aradhya Bhatia <a-bhatia1@xxxxxx>
> ---
> arch/arm64/boot/dts/ti/k3-am62x-sk-common.dtsi | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/arch/arm64/boot/dts/ti/k3-am62x-sk-common.dtsi b/arch/arm64/boot/dts/ti/k3-am62x-sk-common.dtsi
> index 34c8ffc553ec..540ed8a0d7fb 100644
> --- a/arch/arm64/boot/dts/ti/k3-am62x-sk-common.dtsi
> +++ b/arch/arm64/boot/dts/ti/k3-am62x-sk-common.dtsi
> @@ -300,7 +300,7 @@ &main_i2c1 {
> status = "okay";
> pinctrl-names = "default";
> pinctrl-0 = <&main_i2c1_pins_default>;
> - clock-frequency = <400000>;
> + clock-frequency = <100000>;
>
> tlv320aic3106: audio-codec@1b {
> #sound-dai-cells = <0>;
> --
> 2.40.1
>

I know we had issues with level shifters on the dev platform previously,
but do we need this patch anymore with the production boards?

if so, use Fixes and I can pick for next.

--
Regards,
Nishanth Menon
Key (0xDDB5849D1736249D) / Fingerprint: F8A2 8693 54EB 8232 17A3 1A34 DDB5 849D 1736 249D