RUT955 How to use MMC?

Installing and Using OpenWrt
1

Trying to use a microSD, my custom built openwrt does not "see" the card. Having tried the same card on a WE826 (ramips), it worked.
ls /dev on the WE826 showed a mmcblk0
available.
Is somebody using the microSD successfully on the RUT955 ?
If yes, which special packages to install ?

2

You have to enable it in device tree as the driver causes problems when loading without an SD card being inserted. Edit target/linux/ath79/dts/ar9344_teltonika_rut9xx.dtsi:

--- a/target/linux/ath79/dts/ar9344_teltonika_rut9xx.dtsi
+++ b/target/linux/ath79/dts/ar9344_teltonika_rut9xx.dtsi
@@ -102,7 +102,7 @@
        };
 
        microsd@1 {
-               status = "disabled";
+               status = "okay";
 
                compatible = "mmc-spi-slot";
                spi-max-frequency = <25000000>;
3

I did your edit, and there is some progress. Now I see in dmesg:

[   43.641909] mmc_spi spi0.1: setup: unsupported mode bits 4
[   43.647485] mmc_spi spi0.1: can't change chip-select polarity
[   43.653340] mmc_spi spi0.1: spi clock is too low
[   43.670624] mmc_spi spi0.1: SD/MMC host mmc0, no WP, no poweroff, cd polling
...
...
..
[   47.781994] mmc_spi spi0.1: setup: unsupported mode bits 4

Last msg every few seconds repeated.

4

Try increasing spi-max-frequency to 52000000 and see if that helps.

5 
[   20.561884] mmc_spi spi0.1: setup: unsupported mode bits 4
[   20.567460] mmc_spi spi0.1: can't change chip-select polarity
[   20.573315] mmc_spi spi0.1: spi clock is too low
[   20.590609] mmc_spi spi0.1: SD/MMC host mmc0, no WP, no poweroff, cd polling
...[   24.652004] mmc_spi spi0.1: setup: unsupported mode bits 4
[   24.657578] mmc_spi spi0.1: can't change chip-select polarity
[   28.731996] mmc_spi spi0.1: setup: unsupported mode bits 4

Unfortunately, no difference.
Which special kernel-mods to use ? Only

crc_itu_t               1069  1 mmc_spi
crc7                     811  1 mmc_spi
mmc_block              25914  0
mmc_core               88842  3 mmc_spi,of_mmc_spi,mmc_block
mmc_spi                 9362  0
of_mmc_spi               952  1 mmc_spi
6

I can provide org .config, *.dts, *.dtsi from Teltonika, which might help here.
Pls, PM.

7

I got those as well, it's all public and what the support in OpenWrt is based on. Thing is, I no longer have access to the device itself :frowning: It's probably worth investigating if Teltonika made changes to the mmc-spi driver in the kernel (ie. diff against upstream kernel).

8

Official bug filed: FS#3962 - MMC on RUT955 does not work