Re: [PATCH v2] ARM: dts: rockchip: temporarily remove emmc hs200 speed from rk3288-veyron-speedy.

From: Paul Kocialkowski <contact-W9ppeneeCTY@public.gmane.org>
To: Vagrant Cascadian
	<vagrantc-LkDtOWtB3X7R7s880joybQ@public.gmane.org>,
	Heiko Stuebner <heiko-4mtYJXux2i+zQB+pC5nmwQ@public.gmane.org>
Cc: Mark Rutland <mark.rutland-5wv7dgnIgG8@public.gmane.org>,
	devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
	Russell King <linux-I+IVW8TIWO2tmTQ+vhA3Yw@public.gmane.org>,
	linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
	linux-rockchip-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org,
	Rob Herring <robh+dt-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>,
	linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org
Subject: Re: [PATCH v2] ARM: dts: rockchip: temporarily remove emmc hs200 speed from rk3288-veyron-speedy.
Date: Sun, 16 Oct 2016 21:49:43 +0200	[thread overview]
Message-ID: <1476647383.3885.3.camel@paulk.fr> (raw)
In-Reply-To: <87twd1vzc5.fsf-LkDtOWtB3X7R7s880joybQ@public.gmane.org>

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Hi,

Le mardi 27 septembre 2016 à 13:53 -0700, Vagrant Cascadian a écrit :
> This essentially mimics what was done with rk3288-veyron-minnie in
> commit 984926781122f034d5bc9962815d135b6c4a8e1d.
> 
> The eMMC of the speedy Chromebook also appears to need the same tuning
> workaround, as it frequently fails to recognize the eMMC without it.

I have a device where (without this patch) eMMC sometimes fails, with:
[    3.561010] dwmmc_rockchip ff0f0000.dwmmc: Successfully tuned phase to 175
[    3.571742] mmc2: new HS200 MMC card at address 0001
[    3.571943] mmcblk2: mmc2:0001 HAG2e 14.7 GiB 
[    3.572026] mmcblk2boot0: mmc2:0001 HAG2e partition 1 4.00 MiB
[    3.572107] mmcblk2boot1: mmc2:0001 HAG2e partition 2 4.00 MiB
[    3.572181] mmcblk2rpmb: mmc2:0001 HAG2e partition 3 4.00 MiB
[    3.685647] mmcblk2: error -110 transferring data, sector 0, nr 8, cmd response 0x900, card status 0x0

And sometimes works, with:
[    3.451058] dwmmc_rockchip ff0f0000.dwmmc: Successfully tuned phase to 176
[    3.491093] mmc2: new HS200 MMC card at address 0001
[    3.491277] mmcblk2: mmc2:0001 HAG2e 14.7 GiB 
[    3.491345] mmcblk2boot0: mmc2:0001 HAG2e partition 1 4.00 MiB
[    3.491409] mmcblk2boot1: mmc2:0001 HAG2e partition 2 4.00 MiB
[    3.491474] mmcblk2rpmb: mmc2:0001 HAG2e partition 3 4.00 MiB
[    3.493548]  mmcblk2: p1 p2

However, with this change, it always fails, with:
[    3.322129] mmc_host mmc2: Bus speed (slot 0) = 50000000Hz (slot req 52000000Hz, actual 50000000HZ div = 0)
[    3.333174] mmc2: error -110 whilst initialising MMC card

I don't have so much time to investigate this issue, but it's clear that this
patch doesn't fix the issue (and actually worsens it) for my device.

Cheers!

> Signed-off-by: Vagrant Cascadian <vagrantc-LkDtOWtB3X7R7s880joybQ@public.gmane.org>
> ---
> Changes in v2:
>  - Added Signed-off-by.
> 
>  arch/arm/boot/dts/rk3288-veyron-speedy.dts | 5 +++++
>  1 file changed, 5 insertions(+)
> 
> diff --git a/arch/arm/boot/dts/rk3288-veyron-speedy.dts
> b/arch/arm/boot/dts/rk3288-veyron-speedy.dts
> index a0d033f..500fd18 100644
> --- a/arch/arm/boot/dts/rk3288-veyron-speedy.dts
> +++ b/arch/arm/boot/dts/rk3288-veyron-speedy.dts
> @@ -124,6 +124,11 @@
>             &sdmmc_bus4>;
>  };
> 
> +
> +&emmc {
> +       /delete-property/mmc-hs200-1_8v;
> +};
> +
>  &vcc_5v {
>     enable-active-high;
>     gpio = <&gpio7 21 GPIO_ACTIVE_HIGH>;
> _______________________________________________
> Linux-rockchip mailing list
> Linux-rockchip-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org
> http://lists.infradead.org/mailman/listinfo/linux-rockchip
-- 
Paul Kocialkowski, developer of free digital technology at the lower levels

Website: https://www.paulk.fr/
Coding blog: https://code.paulk.fr/
Git repositories: https://git.paulk.fr/ https://git.code.paulk.fr/

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