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From: Chukun Pan <amadeus@jmu.edu.cn>
To: jonas@kwiboo.se
Cc: amadeus@jmu.edu.cn, conor+dt@kernel.org,
	devicetree@vger.kernel.org, heiko@sntech.de, krzk+dt@kernel.org,
	linux-arm-kernel@lists.infradead.org,
	linux-kernel@vger.kernel.org, linux-rockchip@lists.infradead.org,
	naoki@radxa.com
Subject: Re: [PATCH 1/1] arm64: dts: rockchip: default to host mode for USB on Radxa E25
Date: Wed, 15 Jan 2025 10:00:06 +0800	[thread overview]
Message-ID: <20250115020006.10336-1-amadeus@jmu.edu.cn> (raw)
In-Reply-To: <d7b2e993-c6c8-4e60-bfe2-80857ca8a992@kwiboo.se>

Hi,
> I would advise against using any sd-uhs- mode for sd-card on Rockchip
> RK356x boards because of a timing issue during boot between mmc,
> regulator and IO-domain drivers.

This problem seems to occur only on rk356x?

> Ideally this race condition should be solved instead of limiting use
> of UHS modes. However, use of sd-uhs-sdr50 is typically more forgiving
> and has been used on other boards.

It seems that sd-uhs-sdr50 does not need 1.8V IO voltage.
I tested the speed on a rk3528 board with sdio wifi:
(The IO voltage of sdio on this board is 3.3V)

highspeed: 170Mbps DL
sdr50:     290Mbps DL
sdr104:    290Mbps DL

So sdr50 should be safe.

Thanks,
Chukun

-- 
2.25.1


  reply	other threads:[~2025-01-15  2:05 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <20241215083805.1461902-1-amadeus@jmu.edu.cn>
2024-12-15 12:36 ` FUKAUMI Naoki
2024-12-22  4:30   ` Chukun Pan
2024-12-23  2:18     ` FUKAUMI Naoki
2024-12-23  3:00       ` Chukun Pan
2024-12-23 10:50         ` Jonas Karlman
2025-01-15  2:00           ` Chukun Pan [this message]
2024-11-30 14:51 [PATCH v4 4/4] arm64: dts: qcom: ipq6018: add LDOA2 regulator Konrad Dybcio
2024-12-22  4:38 ` [PATCH 1/1] arm64: dts: rockchip: default to host mode for USB on Radxa E25 Chukun Pan

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