Re: [PATCH v3 1/3] arm: dts: rk3288-tinker.dtsi: Fix SD card detection

[Heiko Stuebner <heiko-4mtYJXux2i+zQB+pC5nmwQ@public.gmane.org>]

Am Samstag, 9. März 2019, 16:39:21 CET schrieb David Summers:
> The Problem:
> 
> On ASUS Tinker Board S, when booting from the eMMC, and there is card
> in the sd slot, there are constant errors.
> 
> Also when warm reboot, uboot can not access the sd slot
> 
> Cause:
> 
> Identified by Robin Murphy @ ARM. The Card Detect on rk3288
> devices is pulled up by vccio-sd; so when the regulator powers this
> off, card detect gives spurious errors. A second problem, is during
> power down, vccio-sd apprears to be powered down. This causes a
> problem when warm rebooting from the sd card. This was identified by
> Jonas Karlman.
> 
> History:
> 
> A common fault on these rk3288 board, which impliment the reference
> design.
> 
> When this arose before:
> 
> http://lists.infradead.org/pipermail/linux-arm-kernel/2014-August/281153.html
> 
> And Ulf and Jaehoon clearly said this was a broken card detect design,
> which should be solved via polling
> 
> Solution:
> 
> Hence broken-cd is set as a property. This cures the errors. The
> powering down of vccio-sd during reboot is cured by adding
> regulator-boot-on.
> 
> This solutions has been fairly widely reviewed and tested.
> 
> Signed-off-by: David Summers <beagleboard-8lkWs+DogrrqRUWtDFdff/XRex20P6io@public.gmane.org>
> Reviewed by: Robin Murphy <robin.murphy-5wv7dgnIgG8@public.gmane.org>
> Reviewed by: Jonas Karlman <jonas-uIzNG4q0ceqzQB+pC5nmwQ@public.gmane.org>
> Test by: TheSaint @ ArchLinux Arm

please follow patch submission guidelines, here it would be
Tested-by: ... with an actual Name + mail address

Also I did try to go through the way big mail thread but didn't
find an actual "Reviewed-by" from Robin Murphy, similar to what
he pointed out in patch2

Other than that and including the past discussions, this looks good.


Heiko

> ---
>  arch/arm/boot/dts/rk3288-tinker.dtsi | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/arch/arm/boot/dts/rk3288-tinker.dtsi b/arch/arm/boot/dts/rk3288-tinker.dtsi
> index aa107ee41b8b..ef653c3209bc 100644
> --- a/arch/arm/boot/dts/rk3288-tinker.dtsi
> +++ b/arch/arm/boot/dts/rk3288-tinker.dtsi
> @@ -254,6 +254,7 @@
>  			};
>  
>  			vccio_sd: LDO_REG5 {
> +				regulator-boot-on;
>  				regulator-min-microvolt = <1800000>;
>  				regulator-max-microvolt = <3300000>;
>  				regulator-name = "vccio_sd";
> @@ -430,7 +431,7 @@
>  	bus-width = <4>;
>  	cap-mmc-highspeed;
>  	cap-sd-highspeed;
> -	card-detect-delay = <200>;
> +	broken-cd;
>  	disable-wp;			/* wp not hooked up */
>  	pinctrl-names = "default";
>  	pinctrl-0 = <&sdmmc_clk &sdmmc_cmd &sdmmc_cd &sdmmc_bus4>;
>