在 2026/01/12 星期一 16:29, Chaoyi Chen 写道:

Hi Shawn,

On 1/12/2026 11:56 AM, Shawn Lin wrote:

quoted

在 2026/01/12 星期一 9:32, Shawn Lin 写道:

quoted

在 2026/01/10 星期六 9:07, Marco Schirrmeister 写道:

quoted

This series addresses a microSD stability issue on the FriendlyElec
NanoPi R76S (RK3576). The board currently suffers from a 400kHz
retuning loop when the controller attempts to enter runtime-suspend
during idle periods.

Evidence of the failure in dmesg:
[Fri Jan  2 01:28:02 2026] mmc_host mmc1: Bus speed (slot 0) = 400000Hz
[Fri Jan  2 01:28:03 2026] mmc_host mmc1: Bus speed (slot 0) = 198000000Hz
[Fri Jan  2 01:28:03 2026] dwmmc_rockchip 2a310000.mmc: Successfully tuned phase to 233
[Fri Jan  2 01:28:04 2026] mmc_host mmc1: Bus speed (slot 0) = 400000Hz

Does this problem happen with all microSDs or just *a* microSD per
your description?
Have you ever tried to disable SDR104 support?

A quick update.

I found several problems on RK3576 for supporting sd cards. I wondered
how all upstream RK3576 boards claiming SD support work? Anyway, I sent
a series to the list[1], not sure if it fixes the problem you faced, but
these should be the right patches you should have a try.


[1]https://lore.kernel.org/linux-rockchip/1768189768-96333-1-git-send-email-shawn.lin@rock-chips.com/T/#t (local)

I encountered a similar issue on the RK3576 EVB2.

It seems that the cd-gpios feature are broken, so SD card events

Yes, cd-gpios method for RK3576 is broken now, so you need to apply
my first 2 fix patches.

cannot be detected. However, if the SD card is inserted before Linux
boots, it can at least start up. I suspect that other boards may behave
the same way :)

This is true, because .get_cd() returns card present when booting for
the first time, you the only way for upstream RK3576 boards to use sd 
cards is to insert the card before booting. But then hot-plug case will
not able to work.