How to make SD work in mmc-spi mode on Altera NIOS2 processor running Linux?

Question

linux

Hello.
I have a NIOS2 software processor running Linux with kernel 4.9.76. An SD card is connected to the processor via the Altera spi (3-wire) IP core. The kernel has support for Altera SPI Controller and MMC/SD over SPI.
A section describing the connection has been added to the dts file:

SDcard: [email protected] {
#address-cells = <1>;
#size-cells = <0>;
compatible = "altr,spi-18.0", "altr,spi-1.0";
reg = <0x00000000 0x00000020>;
interrupt-parent = <&nios2_gen2_0>;
interrupts = <3>;
[email protected] {
compatible = "mmc-spi-slot";
spi-max-frequency = <10000000>;
reg=<0x00000000>;
voltage-ranges = <3300 3300>;
status="okay";
}; //end [email protected]
};

When loading the OS, messages are constantly issued mmc0: error -110 whilst initialising SD card
Not very good at working with mmc. I climbed inside the driver with a debugger and saw that an error is generated when the flash drive is initialized in the mmc_wait_for_app_cmd function after successfully reading the OCR and CID registers.
Tried to install another flash. The situation is the same. What could be the problem?

Answer 1

error -110 whilst initialising SD card
What could be the problem?

110 -- ETIMEDOUT. There's still a lot of things happening "after a successful reading of the OCR and CID registers", you need to more accurately determine the place where the error comes from.