Fix ODROID XU4 boot by disabling PROVE_LOCKING in kernel #3158
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ODROID XU4 fails to boot after update to Linux 6.6. Comparing downstream kernel config with upstream exynos defconfig shows it has various lockdep options enabled, and PROVE_LOCKING seems to be the one that causes the issue. It seems it (or any of PROVE_RCU, TRACE_IRQFLAGS or PREEMPTIRQ_TRACEPOINTS) which get enabled along with it) probably triggers some timing issues on the I2C bus, which causes the main PMIC to fail to properly initialize all voltages. Since these options should not have any real impact on our system, the easiest option is to disable them. If we need them, or want to stay closer to upstream defconfig, further debugging is needed. Fixes #3137
sairon
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board/odroid
agners
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Feb 8, 2024
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ODROID XU4 fails to boot after update to Linux 6.6. Comparing downstream kernel config with upstream exynos defconfig shows it has various lockdep options enabled, and PROVE_LOCKING seems to be the one that causes the issue. It seems it (or any of PROVE_RCU, TRACE_IRQFLAGS or PREEMPTIRQ_TRACEPOINTS) which get enabled along with it) probably triggers some timing issues on the I2C bus, which causes the main PMIC to fail to properly initialize all voltages.
Since these options should not have any real impact on our system, the easiest option is to disable them. If we need them, or want to stay closer to upstream defconfig, further debugging is needed.
Fixes #3137