[U-Boot] Writes to FAT broken by bcm2835 sdhost driver

[Anton Gerasimov]

Hi,

For some reasons I need to save environment on RaspberryPi 3 and it
worked well for me in older versions of u-boot, but stopped working in
newer ones. Using bisect I figured out that the commits responsible for
that were c8a73a26d6dd9b7d489e66529fe1412425d8f2d1 and
caf2233b281c03e3e359061a3dfa537d8a25c273, introducing sdhost and pinctrl
drivers respectively.

Versions before these two work well wrt. writing to FAT/saving the
environment.

After these patches when compiled with rpi_3_32b_defconfig, reading
works well, but fatwrite gives

  wait_transfer_complete - still waiting after 10001 retries

and saveenv

  fsm 1, hsts 00000001

When I try to compile with CONFIG_MMC_BCM2835=n
(CONFIG_MMC_SDHCI_BCM2835 is still enabled), neither read nor write works:

  Saving Environment to FAT... Card did not respond to voltage select!
  ** Bad device mmc 0 **
  Failed (1)

Finally with CONFIG_PINCTRL=n u-boot doesn't compile at all (not sure if
it was intended behavior):

  serial_bcm283x_mu.c:162: undefined reference to `pinctrl_get_gpio_mux'
  serial_bcm283x_pl011.c:30: undefined reference to `pinctrl_get_gpio_mux'

Would be grateful for any help with these issues.

Best regargs,
Anton Gerasimov