From: Marco Felsch <m.felsch@pengutronix.de>
To: barebox@lists.infradead.org
Subject: [PATCH] ARM: dts: i.MX8MP: increase off-on delay on the SD Vcc regulator
Date: Tue, 1 Nov 2022 14:30:50 +0100 [thread overview]
Message-ID: <20221101133050.687403-1-m.felsch@pengutronix.de> (raw)
This commit is required to fix the SD card detection mechanism. Without
this commit the SD card (auto-)detection fails when booted from this
sd-card:
mmc1: Query interface conditions failed: -110
mmc1: SD operation condition set timed out
The commit is ported from U-Boot:
| commit 247bbeb74c186963d9365db3136d0285618bd9a7
| Author: Andrey Zhizhikin <andrey.zhizhikin@leica-geosystems.com>
| Date: Sat Dec 5 17:29:17 2020 +0000
|
| ARM: dts: imx8m: increase off-on delay on the SD Vcc regulator
|
| Some SD Card controller and power circuitry has increased capacitance,
| which keeps the internal logic remains powered after regulator is switch
| off. This is generally the case when card is switched to SD104 mode,
| where a power cycle should be performed. In case if the card internal
| logic remains powered, it causes a subsequent failure of mode
| transition, effectively leading to failed enumeration.
|
| Introduce a delay of 20 msec in order to provide a possibility for
| internal card circuitry to drain voltages and perform a power cycle
| correctly.
|
| Similar fix is done in commit c49d0ac38a76 ("ARM: dts: rmobile: Increase
| off-on delay on the SD Vcc regulator") targeted Renesas SOCs.
|
| Signed-off-by: Andrey Zhizhikin <andrey.zhizhikin@leica-geosystems.com>
| Cc: Stefano Babic <sbabic@denx.de>
Signed-off-by: Marco Felsch <m.felsch@pengutronix.de>
---
arch/arm/dts/imx8mp-evk.dts | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/arch/arm/dts/imx8mp-evk.dts b/arch/arm/dts/imx8mp-evk.dts
index 3264ade4b8..77b438287c 100644
--- a/arch/arm/dts/imx8mp-evk.dts
+++ b/arch/arm/dts/imx8mp-evk.dts
@@ -35,6 +35,10 @@
reset-deassert-us = <100000>;
};
+®_usdhc2_vmmc {
+ off-on-delay-us = <20000>;
+};
+
&usdhc2 {
#address-cells = <1>;
#size-cells = <1>;
--
2.30.2
next reply other threads:[~2022-11-01 13:32 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-11-01 13:30 Marco Felsch [this message]
2022-11-02 8:13 ` Sascha Hauer
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