Re: [PATCH v2 8/8] arm64: dts: rockchip: Enable SD-card interface on Radxa E20C

From: Yao Zi <ziyao@disroot.org>
To: Chukun Pan <amadeus@jmu.edu.cn>
Cc: conor+dt@kernel.org, cristian.ciocaltea@collabora.com,
	detlev.casanova@collabora.com, devicetree@vger.kernel.org,
	heiko@sntech.de, jonas@kwiboo.se, krzk+dt@kernel.org,
	linux-arm-kernel@lists.infradead.org, linux-clk@vger.kernel.org,
	linux-kernel@vger.kernel.org, linux-rockchip@lists.infradead.org
Subject: Re: [PATCH v2 8/8] arm64: dts: rockchip: Enable SD-card interface on Radxa E20C
Date: Fri, 7 Mar 2025 05:52:42 +0000	[thread overview]
Message-ID: <Z8qJqpUwi7VV8tJk@pie> (raw)
In-Reply-To: <20250307033508.656479-1-amadeus@jmu.edu.cn>

On Fri, Mar 07, 2025 at 11:35:08AM +0800, Chukun Pan wrote:
> Hi,
> 
> > +&sdmmc {
> > +	bus-width = <4>;
> > +	cap-mmc-highspeed;
> > +	cap-sd-highspeed;
> > +	disable-wp;
> > +	no-sdio;
> 
> With 'no-sdio' property:
> [  129.608986] mmc_host mmc1: Bus speed (slot 0) = 400000Hz (slot req 400000Hz, actual 400000HZ div = 0)
> [  130.711168] mmc1: Card stuck being busy! __mmc_poll_for_busy
> [  130.725536] mmc_host mmc1: Bus speed (slot 0) = 300000Hz (slot req 300000Hz, actual 300000HZ div = 0)
> [  131.751240] mmc1: Card stuck being busy! __mmc_poll_for_busy
> [  131.765608] mmc_host mmc1: Bus speed (slot 0) = 200000Hz (slot req 200000Hz, actual 200000HZ div = 0)
> [  132.825083] mmc1: Card stuck being busy! __mmc_poll_for_busy
> [  132.839413] mmc_host mmc1: Bus speed (slot 0) = 187500Hz (slot req 187500Hz, actual 187500HZ div = 0)
> [  133.960141] mmc1: Card stuck being busy! __mmc_poll_for_busy
> 
> Without 'no-sdio' property:
> [  105.224019] mmc1: error -22 whilst initialising SDIO card
> [  106.290838] mmc1: Card stuck being busy! __mmc_poll_for_busy
> [  106.801931] dwmmc_rockchip ffc30000.mmc: Busy; trying anyway
> [  107.385835] mmc_host mmc1: Timeou sending command (cmd 0x202000 arg 0x0 status 0x80202000)
> [  107.400425] mmc_host mmc1: Bus speed (slot 0) = 300000Hz (slot req 300000Hz, actual 300000HZ div = 0)
> [  107.431561] mmc_host mmc1: Bus speed (slot 0) = 49800000Hz (slot req 50000000Hz, actual 49800000HZ div = 0)
> [  107.433107] mmc1: new high speed SDIO card at address 0001

So it seems the sdmmc controller actually works with SDIO commands as
well? I don't expect that since the datasheet says RK3528 has only two
SDIO 3.0 controllers.

We could remove the "no-sdio" property if SDIO actually works. Will
apply it in the next version if there's no objection against this.

Further tests about the capabilities of the controller are welcome.

> # cat /sys/kernel/debug/mmc1/ios
> clock:          50000000 Hz
> vdd:            21 (3.3 ~ 3.4 V)
> bus mode:       2 (push-pull)
> chip select:    0 (don't care)
> power mode:     2 (on)
> bus width:      2 (4 bits)
> timing spec:    2 (sd high-speed)
> signal voltage: 0 (3.30 V)
> driver type:    0 (driver type B)
> 
> Thanks,
> Chukun
> 
> -- 
> 2.25.1
> 

Best regards,
Yao Zi