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i.MX8MQ Boot issue at cold Temperature (<0 C)

Question asked by NIRMAL LUHANA on Sep 24, 2019
Latest reply on Sep 30, 2019 by igorpadykov

Hello,

 

Release: Yocto-Sumo (4.14.78_1.0.0_GA)

Board: i.MX8MQ based custom board

 

We have facing cold boot issue in iMX8MQ based custom board.

As we decrease the temperature below 0C our board not booting up and stuck after the DDR training logs.

It will start booting automatically after CPU junction temperature exceeds the 8C.

Attached logs for reference.

 

U-Boot SPL 2018.03-master_v2018.03+g2e7c702 (Sep 02 2019 - 08:56:08 +0000)
PMIC: PFUZE100 ID=0x10
DDRINFO: start lpddr4 ddr init
DRAM PHY training for 3200MTS
check ddr4_pmu_train_imem code
check ddr4_pmu_train_imem code pass
check ddr4_pmu_train_dmem code
check ddr4_pmu_train_dmem code pass
Training PASS
DRAM PHY training for 667MTS
check ddr4_pmu_train_imem code
check ddr4_pmu_train_imem code pass
check ddr4_pmu_train_dmem code
check ddr4_pmu_train_dmem code pass
Training PASS
DRAM PHY training for 3200MTS
check ddr4_pmu_train_imem code
check ddr4_pmu_train_imem code pass
check ddr4_pmu_train_dmem code
check ddr4_pmu_train_dmem code pass
Training PASS
DDRINFO:ddrphy calibration done
DDRINFO: ddrmix config done
Normal Boot
Trying to boot from MMC1


U-Boot 2018.03-master_v2018.03+g2e7c702 (Sep 02 2019 - 08:56:08 +0000)

CPU: Freescale i.MX8MQ rev2.0 1300 MHz (running at 800 MHz)
CPU: Industrial temperature grade (-40C to 105C)

 

Also, we are not getting negative temperature values of CPU junction temperature. For, that we need to apply some patch to get the negative temperature values as per below thread.

Link: Temperature monitor of IMX6UL doesn't work as expected 

 

1) Can anyone please provide the patch to get negative temperature values.

2) For the cold boot issue, we need to do any changes from firmware side? 

 

Best regards,

Nirmal

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