Error fsl_esdhc: Internal clock never stabilised.

[Pali Rohár]

Hello!

U-Boot prints error "fsl_esdhc: Internal clock never stabilised." on
P2020 everytime when trying to access SD card. It happens with every
tested SD card. Note that both read and write operation with SD card is
working fine, U-Boot just prints that noisy error.

For example:

  SD boot...
  No max bus width provided. Assume 8-bit supported.
  Second program loader running in sram...
  fsl_esdhc: Internal clock never stabilised.
  fsl_esdhc: Internal clock never stabilised.
  fsl_esdhc: Internal clock never stabilised.
  fsl_esdhc: Internal clock never stabilised.
  fsl_esdhc: Internal clock never stabilised.
  fsl_esdhc: Internal clock never stabilised.
  fsl_esdhc: Internal clock never stabilised.
  fsl_esdhc: Internal clock never stabilised.
  fsl_esdhc: Internal clock never stabilised.
  fsl_esdhc: Internal clock never stabilised.
  fsl_esdhc: Internal clock never stabilised.
  fsl_esdhc: Internal clock never stabilised.
  fsl_esdhc: Internal clock never stabilised.

Or:

  => mmc info
  fsl_esdhc: Internal clock never stabilised.
  fsl_esdhc: Internal clock never stabilised.
  fsl_esdhc: Internal clock never stabilised.
  fsl_esdhc: Internal clock never stabilised.
  fsl_esdhc: Internal clock never stabilised.
  fsl_esdhc: Internal clock never stabilised.
  fsl_esdhc: Internal clock never stabilised.
  fsl_esdhc: Internal clock never stabilised.
  fsl_esdhc: Internal clock never stabilised.
  fsl_esdhc: Internal clock never stabilised.
  fsl_esdhc: Internal clock never stabilised.
  fsl_esdhc: Internal clock never stabilised.
  fsl_esdhc: Internal clock never stabilised.
  fsl_esdhc: Internal clock never stabilised.
  Device: FSL_SDHC
  Manufacturer ID: 3
  OEM: 5344
  Name: SA16G
  Bus Speed: 50000000
  Mode: SD High Speed (50MHz)
  Rd Block Len: 512
  SD version 3.0
  High Capacity: Yes
  Capacity: 14.8 GiB
  Bus Width: 1-bit
  Erase Group Size: 512 Bytes

I tried to bisect this error and I figured out that U-Boot prints this
error since beginning when this error message was added into fsl_esdhc
driver.

Do you have any idea what is wrong? And how to fix it?