On Wed, Dec 30, 2020 at 12:19:04AM +0100, Bert Vermeulen wrote: > +static inline void wait_ready(struct rtspi *rtspi) > +{ > + while (!(readl(REG(RTL8380_SPI_SFCSR)) & RTL8380_SPI_SFCSR_RDY)) > + ; > +} I'd suggest calling cpu_relax() in the loop's body. > + err = devm_spi_register_controller(&pdev->dev, ctrl); Since you're invoking devm_spi_register_controller() on probe, the controller must not be unregistered explicitly on remove. So the ->remove hook can be dropped altogether: > +static int realtek_spi_remove(struct platform_device *pdev) > +{ > + struct spi_controller *ctrl = platform_get_drvdata(pdev); > + > + spi_unregister_controller(ctrl); > + > + return 0; > +} [...] > + .remove = realtek_spi_remove, The ->probe hook otherwise LGTM. Thanks, Lukas