mx4sio: SD card wakeup fails to initialize certain brands (SanDisk) & appears to violate spec.

[indrora]

In mx4sio, there's an open question on why SanDisk SD cards are failing to initialize. After several changes to the hardware with no avail, I've begun to suspect that it's got something to do with the software wakeup.

There's a lot of logic in the SD card wakeup that feels like it's trying to be "smart".

https://github.com/ps2dev/ps2sdk/blob/3eec5ef99ecf7f6ca85dd6c208edfdd77713ebb1/iop/sio/mx4sio_bd/src/spi_sdcard_driver.c

It also doesn't follow the physical layer spec described by the SD association: https://www.sdcard.org/downloads/pls/

[rickgaiser]

Please read the following: #189

Quoting myself:

"We are using the serial ports in a way they where not made for. This results in so many problems that I'm not sure we can reliably use this interface"

"I will not continue working on this driver, so I'm hoping it's somewhat usefull in it's current state, and that others can continue the work."

[qnox32]

Two of my SanDisk SD cards are now working with this change: #402