A typical scenario is: when XIP on PSRAM enabled, compiler optimization level is Os. Under certain binary layout, boot hangs and backtrace points to `esp_sleep_config_gpio_isolate`.
The root cause is that, during PSRAM initialization, it calls esp_gpio_reserve, which happens to place before the reported function. However, after call, there is no barrier before the clock adjustment in `mspi_timing_enter_low_speed_mode`. The clock gets changed when the cache is still fetching data, resulting in the corrupted data in the end of the cache line.
This commits add spi_flash_disable_cache as a barrier to make sure the cache transactions is finished before the clock switch.
Xiao Xufeng
Laukik Hase