Re: [PATCH 2/6] arm64: dts: rockchip: Add Radxa ROCK 2A/2F

[Yao Zi <ziyao@disroot.org>]

On Tue, Jul 08, 2025 at 10:48:52PM +0000, Jonas Karlman wrote:
> The ROCK 2A and ROCK 2F is a high-performance single board computer
> developed by Radxa, based on the Rockchip RK3528A SoC.
> 
> Add initial device tree for the Radxa ROCK 2A and ROCK 2F boards.
> 
> Signed-off-by: Jonas Karlman <jonas@kwiboo.se>
> ---
> Schematics:
> - https://dl.radxa.com/rock2/2a/v1.2/radxa_rock_2a_v1.2_schematic.pdf
> - https://dl.radxa.com/rock2/2f/radxa_rock2f_v1.01_schematic.pdf
> ---
>  arch/arm64/boot/dts/rockchip/Makefile         |   2 +
>  .../boot/dts/rockchip/rk3528-rock-2.dtsi      | 292 ++++++++++++++++++
>  .../boot/dts/rockchip/rk3528-rock-2a.dts      |  82 +++++
>  .../boot/dts/rockchip/rk3528-rock-2f.dts      |  10 +
>  4 files changed, 386 insertions(+)
>  create mode 100644 arch/arm64/boot/dts/rockchip/rk3528-rock-2.dtsi
>  create mode 100644 arch/arm64/boot/dts/rockchip/rk3528-rock-2a.dts
>  create mode 100644 arch/arm64/boot/dts/rockchip/rk3528-rock-2f.dts
 
While testing the patch on my Rock 2A board, I noticed one of my SDcard
that works perfectly on Radxa E20C and NanoPi Zero 2 cannot be correctly
read out under UHS-125-SDR mode,

	# dd if=/dev/mmcblk1 of=/dev/null bs=4M count=4
	[   18.616828] mmc_host mmc1: Bus speed (slot 0) = 400000Hz (slot req 400000Hz, actual 400000HZ div = 0)
	[   19.193315] mmc1: Skipping voltage switch
	[   19.202046] mmc1: tried to HW reset card, got error -110
	[   19.213312] mmcblk1: recovery failed!
	[   19.213709] I/O error, dev mmcblk1, sector 0 op 0x0:(READ) flags 0x80700 phys_seg 256 prio class 0
	[   19.225201] mmcblk1: recovery failed!
	[   19.225530] I/O error, dev mmcblk1, sector 0 op 0x0:(READ) flags 0x0 phys_seg 1 prio class 0
	[   19.226283] Buffer I/O error on dev mmcblk1, logical block 0, async page read
	dd: /dev/mmcblk1: I/O error

which could be reproduced stably.

the SDMMC controller issued interesting messages during the tuning
process,

	[    0.665246] mmc_host mmc1: Bus speed (slot 0) = 148500000Hz (slot req 150000000Hz, actual 148500000HZ div = 0)
	[    0.851940] dwmmc_rockchip ffc30000.mmc: All phases work, using default phase 90.

but actually it doesn't work with phase = 90. If the frequency is
limited to 100MHz with max-frequency = <100000000> instead of the
default 150MHz, tuning results in a very different phase,

	[    0.665483] mmc_host mmc1: Bus speed (slot 0) = 99600000Hz (slot req 100000000Hz, actual 99600000HZ div = 0)
	[    1.166340] dwmmc_rockchip ffc30000.mmc: Successfully tuned phase to 141

and the card works, too. If I set rockchip,default-sample-phase to 141
in devicetree, the card could work at full 150MHz as well.

I think there's something wrong with the tuning process, or the board's
design cannot always run reliably at 150MHz.

Could you reproduce similar failures on Radxa 2A? If so, it may be
necessary to lower the SDMMC's maximum frequency for the board.

Regards,
Yao Zi