E.g. the baro_ms5611_spi module runs this function at 40Hz, so it will take even longer, but probably doesn't matter...
In any case it misses a check for `ms->spi_trans.status == SPITransDone`

Also you are not even using the ms5611_event function on chibios and instead duplicate it in periodic_check (which is only meant to ensure long enough delay between the two conversions).
And the ms5611_spi_read function is meant to trigger one new measurement.