On 15/02/16 18:12, Guenter Roeck wrote:

[...]

I added some debugging on top of your patch, and get:

platform basic-mmio-gpio.1.auto: Device node exists
[/smb/motherboard/iofpga at 7,00000000/sysreg at 00000/sys_led at 08],
of_driver_match_device() failed
platform basic-mmio-gpio.1.auto: platform_match_id() succeeded
platform basic-mmio-gpio.2.auto: Device node exists
[/smb/motherboard/iofpga at 7,00000000/sysreg at 00000/sys_mci at 48],
of_driver_match_device() failed
platform basic-mmio-gpio.2.auto: platform_match_id() succeeded
platform basic-mmio-gpio.3.auto: Device node exists
[/smb/motherboard/iofpga at 7,00000000/sysreg at 00000/sys_flash at 4c],
of_driver_match_device() failed
platform basic-mmio-gpio.3.auto: platform_match_id() succeeded

So it isn't the mmc driver failing to instantiate directly,
but (I think) vexpress-sysreg.

That's correct, I could reproduce this issue and reported with similar
analysis earlier [1]

--
Regards,
Sudeep

[1] http://www.spinics.net/lists/arm-kernel/msg483107.html