I've observed sgtl5000 fill defaults error, with Linux upstream kernel and I couldn't see playback working. here is the log and any inputs please let me know.
# dmesg | grep sgtl
[ 2.385948] sgtl5000 2-000a: sgtl5000 revision 0x11
[ 2.449535] sgtl5000 2-000a: sgtl5000_fill_defaults: error -6 setting reg 0x02 to 0x0000
[ 2.454457] sgtl5000 2-000a: sgtl5000_fill_defaults: error -6 setting reg 0x06 to 0x0010
[ 2.462632] sgtl5000 2-000a: sgtl5000_fill_defaults: error -6 setting reg 0x0a to 0x0010
[ 2.470810] sgtl5000 2-000a: sgtl5000_fill_defaults: error -6 setting reg 0x0e to 0x020c
[ 2.478930] sgtl5000 2-000a: sgtl5000_fill_defaults: error -6 setting reg 0x10 to 0x3c3c
[ 2.487105] sgtl5000 2-000a: sgtl5000_fill_defaults: error -6 setting reg 0x14 to 0x015f
[ 2.495283] sgtl5000 2-000a: sgtl5000_fill_defaults: error -6 setting reg 0x20 to 0x0000
[ 2.503560] sgtl5000 2-000a: sgtl5000_fill_defaults: error -6 setting reg 0x22 to 0x1818
[ 2.511746] sgtl5000 2-000a: sgtl5000_fill_defaults: error -6 setting reg 0x24 to 0x0111
[ 2.519896] sgtl5000 2-000a: sgtl5000_fill_defaults: error -6 setting reg 0x28 to 0x0000
[ 2.528045] sgtl5000 2-000a: sgtl5000_fill_defaults: error -6 setting reg 0x2a to 0x0000
[ 2.536221] sgtl5000 2-000a: sgtl5000_fill_defaults: error -6 setting reg 0x2c to 0x0000
[ 2.544371] sgtl5000 2-000a: sgtl5000_fill_defaults: error -6 setting reg 0x2e to 0x0404
[ 2.552556] sgtl5000 2-000a: sgtl5000_fill_defaults: error -6 setting reg 0x32 to 0x5000
[ 2.560736] sgtl5000 2-000a: sgtl5000_fill_defaults: error -6 setting reg 0x34 to 0x0000
[ 2.568854] sgtl5000 2-000a: sgtl5000_fill_defaults: error -6 setting reg 0x36 to 0x0000
[ 2.577027] sgtl5000 2-000a: sgtl5000_fill_defaults: error -6 setting reg 0x3c to 0x0000
[ 2.585207] sgtl5000 2-000a: sgtl5000_fill_defaults: error -6 setting reg 0x3a to 0x0000
[ 2.593356] sgtl5000 2-000a: sgtl5000_fill_defaults: error -6 setting reg 0x100 to 0x0000
[ 2.601535] sgtl5000 2-000a: sgtl5000_fill_defaults: error -6 setting reg 0x102 to 0x0000
[ 2.609815] sgtl5000 2-000a: sgtl5000_fill_defaults: error -6 setting reg 0x104 to 0x0040
[ 2.618021] sgtl5000 2-000a: sgtl5000_fill_defaults: error -6 setting reg 0x106 to 0x051f
[ 2.626282] sgtl5000 2-000a: sgtl5000_fill_defaults: error -6 setting reg 0x108 to 0x0000
[ 2.634547] sgtl5000 2-000a: sgtl5000_fill_defaults: error -6 setting reg 0x10a to 0x0040
[ 2.642783] sgtl5000 2-000a: sgtl5000_fill_defaults: error -6 setting reg 0x116 to 0x002f
[ 2.651049] sgtl5000 2-000a: sgtl5000_fill_defaults: error -6 setting reg 0x118 to 0x002f
[ 2.659282] sgtl5000 2-000a: sgtl5000_fill_defaults: error -6 setting reg 0x11a to 0x002f
[ 2.667511] sgtl5000 2-000a: sgtl5000_fill_defaults: error -6 setting reg 0x11c to 0x002f
[ 2.675790] sgtl5000 2-000a: sgtl5000_fill_defaults: error -6 setting reg 0x11e to 0x002f
[ 2.684055] sgtl5000 2-000a: sgtl5000_fill_defaults: error -6 setting reg 0x120 to 0x8000
[ 2.692291] sgtl5000 2-000a: sgtl5000_fill_defaults: error -6 setting reg 0x122 to 0x0000
[ 2.700557] sgtl5000 2-000a: sgtl5000_fill_defaults: error -6 setting reg 0x124 to 0x0510
[ 2.708791] sgtl5000 2-000a: sgtl5000_fill_defaults: error -6 setting reg 0x126 to 0x1473
[ 2.717022] sgtl5000 2-000a: sgtl5000_fill_defaults: error -6 setting reg 0x128 to 0x0028
[ 2.725287] sgtl5000 2-000a: sgtl5000_fill_defaults: error -6 setting reg 0x12a to 0x0050
[ 2.768986] imx-sgtl5000 sound: sgtl5000 <-> 2028000.ssi mapping ok
[ 2.975587] #0: imx6q-icore-sgtl5000
