Re: [PATCH v5 2/2] spi: Add generic SPI multiplexer

From: Nicolas Saenz Julienne
Date: Fri Nov 13 2020 - 10:47:05 EST


Upon registering spi-mux's devices through spi_add_device() the kernel gets
stuck waiting for the 'spi_add_lock' mutex to be released. The mutex happens to
be held by spi-mux's parent SPI bus, which unluckily, is waiting for spi-mux's
probe to finish before releasing it.

I might aswell be doing something wrong. But so far I trust my DT
implementation:

&spi {
status = "okay";
pinctrl-names = "default";
pinctrl-0 = <&spi0_gpio7>;

spi@0 {
compatible = "spi-mux";
reg = <0>;
#address-cells = <1>;
#size-cells = <0>;
spi-max-frequency = <100000000>;

mux-controls = <&gpio_mux>;

w5500@0 {
compatible = "wiznet,w5500";
reg = <0>;
pinctrl-names = "default";
pinctrl-0 = <&eth1_pins>;
interrupt-parent = <&gpio>;
interrupts = <27 IRQ_TYPE_EDGE_FALLING>;
spi-max-frequency = <30000000>;
};

spi-flash@1 {
compatible = "jedec,spi-nor";
reg = <1>;
#address-cells = <1>;
#size-cells = <0>;
spi-max-frequency = <16000000>;
};
};
};

Regards,
Nicolas