rk3399 TPL memory setup code triggers clock frequency limit assertion

["Michal Suchánek" <msuchanek@suse.de>]

Hello,

when compiled with clock debug rk3399 cannot be booted because memory
setup code triggers clock assertion:

U-Boot TPL 2022.07-00038-g61e11a8e9f-dirty (Aug 07 2022 - 16:13:17)
TPL PLL at ff760000: fbdiv=50, refdiv=1, postdiv1=2, postdiv2=1, vco=1200000 khz, output=600000 khz
TPL PLL at ff760020: fbdiv=50, refdiv=1, postdiv1=2, postdiv2=1, vco=1200000 khz, output=600000 khz
TPL PLL at ff760080: fbdiv=99, refdiv=2, postdiv1=2, postdiv2=1, vco=1188000 khz, output=594000 khz
TPL PLL at ff760060: fbdiv=64, refdiv=1, postdiv1=2, postdiv2=2, vco=1536000 khz, output=384000 khz
TPL PLL at ff760040: fbdiv=12, refdiv=1, postdiv1=3, postdiv2=2, vco=288000 khz, output=48000 khz
drivers/clk/rockchip/clk_rk3399.c:347: rkclk_set_pll: Assertion `vco_khz >= VCO_MIN_KHZ && vco_khz <= VCO_MAX_KHZ && output_khz >= OUTPUT_MIN_KHZ && output_khz <= OUTPUT_MAX_KHZ && div->fbdiv >= PLL_DIV_MIN && div->fbdiv <= PLL_DIV_MAX' failed.Channel 0: LPDDR4, 50MHz
BW=32 Col=10 Bk=8 CS0 Row=15 CS1 Row=15 CS=2 Die BW=16 Size=2048MB
Channel 1: LPDDR4, 50MHz
BW=32 Col=10 Bk=8 CS0 Row=15 CS1 Row=15 CS=2 Die BW=16 Size=2048MB
256B stride
TPL PLL at ff760040: fbdiv=50, refdiv=1, postdiv1=3, postdiv2=1, vco=1200000 khz, output=400000 khz
lpddr4_set_rate: change freq to 400000000 mhz 0, 1
TPL PLL at ff760040: fbdiv=100, refdiv=1, postdiv1=3, postdiv2=1, vco=2400000 khz, output=800000 khz
lpddr4_set_rate: change freq to 800000000 mhz 1, 0
Trying to boot from BOOTROM
Returning to boot ROM...
SPL PLL at ff760000: fbdiv=50, refdiv=1, postdiv1=2, postdiv2=1, vco=1200000 khz, output=600000 khz
SPL PLL at ff760020: fbdiv=50, refdiv=1, postdiv1=2, postdiv2=1, vco=1200000 khz, output=600000 khz
SPL PLL at ff760080: fbdiv=99, refdiv=2, postdiv1=2, postdiv2=1, vco=1188000 khz, output=594000 khz
SPL PLL at ff760060: fbdiv=64, refdiv=1, postdiv1=2, postdiv2=2, vco=1536000 khz, output=384000 khz

U-Boot SPL 2022.07-00038-g61e11a8e9f-dirty (Aug 07 2022 - 16:13:17 +0200)
mmc@fe320000: Got clock clock-controller@ff760000 76
Trying to boot from MMC2
NOTICE:  BL31: v2.6(debug):
NOTICE:  BL31: Built : 14:50:40, Jul  1 2022
INFO:    GICv3 with legacy support detected.
INFO:    ARM GICv3 driver initialized in EL3
INFO:    Maximum SPI INTID supported: 287
INFO:    plat_rockchip_pmu_init(1624): pd status 3e
INFO:    BL31: Initializing runtime services
INFO:    BL31: cortex_a53: CPU workaround for 855873 was applied
WARNING: BL31: cortex_a53: CPU workaround for 1530924 was missing!
INFO:    BL31: Preparing for EL3 exit to normal world
INFO:    Entry point address = 0x200000
INFO:    SPSR = 0x3c9

Clearly the assertion is wrong at least for this PLL because the system
boots with the assertion disarmed. Then again, it is not clear that the
PLL is operated at this frequency at all - it is immediately changed to
higher frequency when the memory type is detected.

What would be a resonable way to make rk3399 bootable with clock debug
enabled?

Thanks

Michal