Re: [PATCH] ARM: dts: imx8mq-evk: Remove u-boot, off-on-delay-us property
On Mon, Feb 22, 2021 at 11:14 PM Peng Fan (OSS) wrote: > See > https://source.codeaurora.org/external/imx/linux-imx/tree/arch/arm64/boot/dts/freescale/imx8mq-evk.dts?h=imx_5.4.70_2.3.0#n100 > > NXP vendor tree has off-on-delay-us. Ok, but are you able to determine the appropriate off-on-delay-us for imx8mq-evk in U-Boot to avoid the existing regression?
RE: [PATCH] ARM: dts: imx8mq-evk: Remove u-boot,off-on-delay-us property
> Subject: Re: [PATCH] ARM: dts: imx8mq-evk: Remove u-boot,off-on-delay-us > property > > Hi Peng, > > On Mon, Feb 22, 2021 at 10:53 PM Peng Fan wrote: > > > It is board dependent, some board may has a big capacitance, the > > off-on-delay is to give enough time for the capacitance to leak its > > voltage. > > Ok, but not clear from your comment if you agree with my change or not. I think remove it is not correct, the exact time should be measured using oscilloscope, removing it might make sd3.0 not work. But anyway 2 seems too large a value. Regards, Peng. > > Please clarify.
RE: [PATCH] ARM: dts: imx8mq-evk: Remove u-boot,off-on-delay-us property
Hi Fabio,
> Subject: [PATCH] ARM: dts: imx8mq-evk: Remove u-boot,off-on-delay-us
> property
>
> Commit 247bbeb74c18 ("ARM: dts: imx8m: increase off-on delay on the SD
> Vcc
> regulator") caused the imx8mq-evk board to not be able to store the
> environment variables in the SD card.
>
> Remove the u-boot,off-on-delay-us property to fix the regression.
It is board dependent, some board may has a big capacitance,
the off-on-delay is to give enough time for the capacitance
to leak its voltage.
Regards,
Peng.
>
> Signed-off-by: Fabio Estevam
> ---
> arch/arm/dts/imx8mq-evk-u-boot.dtsi | 4
> 1 file changed, 4 deletions(-)
>
> diff --git a/arch/arm/dts/imx8mq-evk-u-boot.dtsi
> b/arch/arm/dts/imx8mq-evk-u-boot.dtsi
> index 44af66372712..2cfc12b7e0a4 100644
> --- a/arch/arm/dts/imx8mq-evk-u-boot.dtsi
> +++ b/arch/arm/dts/imx8mq-evk-u-boot.dtsi
> @@ -1,9 +1,5 @@
> // SPDX-License-Identifier: (GPL-2.0 OR MIT)
>
> -®_usdhc2_vmmc {
> - u-boot,off-on-delay-us = <2>;
> -};
> -
> &usdhc1 {
> mmc-hs400-1_8v;
> };
> --
> 2.25.1
RE: [PATCH] ARM: dts: imx8mq-evk: Remove u-boot,off-on-delay-us property
> -Original Message- > From: Fabio Estevam [mailto:feste...@gmail.com] > Sent: 2021年2月23日 10:11 > To: Peng Fan > Cc: sba...@denx.de; u-boot@lists.denx.de; tr...@konsulko.com; > loru...@gmail.com; andrey.zhizhi...@leica-geosystems.com > Subject: Re: [PATCH] ARM: dts: imx8mq-evk: Remove u-boot,off-on-delay-us > property > > On Mon, Feb 22, 2021 at 11:04 PM Peng Fan wrote: > > > I think remove it is not correct, the exact time should be measured > > using oscilloscope, removing it might make sd3.0 not work. But anyway > > 2 seems too large a value. > > Do you plan to submit a fix for this then? If you don't have the bandwidth for > working on this, then we could go with my proposal. > > I would like to be able to boot a kernel from the SD card in the > 2021.04 release and fix the regression. > > Also, why don't we have such property in the imx8mq-evk.dts in the kernel? > > I don't think U-Boot dts should deviate from the Linux devicetree in this > aspect. See https://source.codeaurora.org/external/imx/linux-imx/tree/arch/arm64/boot/dts/freescale/imx8mq-evk.dts?h=imx_5.4.70_2.3.0#n100 NXP vendor tree has off-on-delay-us. Regards Peng.
Re: [PATCH] ARM: dts: imx8mq-evk: Remove u-boot, off-on-delay-us property
On Mon, Feb 22, 2021 at 11:04 PM Peng Fan wrote: > I think remove it is not correct, the exact time should be measured using > oscilloscope, removing it might make sd3.0 not work. But anyway 2 seems > too large a value. Do you plan to submit a fix for this then? If you don't have the bandwidth for working on this, then we could go with my proposal. I would like to be able to boot a kernel from the SD card in the 2021.04 release and fix the regression. Also, why don't we have such property in the imx8mq-evk.dts in the kernel? I don't think U-Boot dts should deviate from the Linux devicetree in this aspect.
Re: [PATCH] ARM: dts: imx8mq-evk: Remove u-boot, off-on-delay-us property
Hi Peng, On Mon, Feb 22, 2021 at 10:53 PM Peng Fan wrote: > It is board dependent, some board may has a big capacitance, > the off-on-delay is to give enough time for the capacitance > to leak its voltage. Ok, but not clear from your comment if you agree with my change or not. Please clarify.
RE: [PATCH] ARM: dts: imx8mq-evk: Remove u-boot,off-on-delay-us property
Hello Fabio,
Thanks for taking care of this!
I believe this fix still applies to mx8m mini series, as without it - some SD
Cards are failed to be recognized.
> -Original Message-
> From: Fabio Estevam
> Sent: Monday, February 22, 2021 6:41 PM
> To: sba...@denx.de
> Cc: u-boot@lists.denx.de; trini ; loru...@gmail.com;
> ZHIZHIKIN Andrey ;
> peng@nxp.com; Fabio Estevam
> Subject: [PATCH] ARM: dts: imx8mq-evk: Remove u-boot,off-on-delay-us
> property
>
>
> Commit 247bbeb74c18 ("ARM: dts: imx8m: increase off-on delay on the SD Vcc
> regulator") caused the imx8mq-evk board to not be able to store the
> environment variables in the SD card.
>
> Remove the u-boot,off-on-delay-us property to fix the regression.
>
> Signed-off-by: Fabio Estevam
> ---
> arch/arm/dts/imx8mq-evk-u-boot.dtsi | 4
> 1 file changed, 4 deletions(-)
>
> diff --git a/arch/arm/dts/imx8mq-evk-u-boot.dtsi b/arch/arm/dts/imx8mq-evk-
> u-boot.dtsi
> index 44af66372712..2cfc12b7e0a4 100644
> --- a/arch/arm/dts/imx8mq-evk-u-boot.dtsi
> +++ b/arch/arm/dts/imx8mq-evk-u-boot.dtsi
> @@ -1,9 +1,5 @@
> // SPDX-License-Identifier: (GPL-2.0 OR MIT)
>
> -®_usdhc2_vmmc {
> - u-boot,off-on-delay-us = <2>;
> -};
> -
> &usdhc1 {
> mmc-hs400-1_8v;
> };
> --
> 2.25.1
Reviewed-by: Andrey Zhizhikin
