I have a Wifi module based on 8797 Marvell chipset and it using SDIO 3.0. The sdio controller (drivers/mmc/core/sdio.c) switched the speed to 4bit mode since the 8797 supports it.
The problem right now, the host controller and the 8797 couldn't communicate to each other correctly, if the speed is set to 4bit mode. Then, if I set it to a 1bit mode, the two can communicate correctly. Also, I tried the SDHCI controller to use the ADMA then SDMA, but both of them are no effect.
I would like to know if anyone have resolved the issue or anyone has idea how to fix it?