Sebastian, On Fri, Sep 25, 2020 at 5:18 PM Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx> wrote: > - try a later kernel (v5.9) > - implement ->write_atomic() and make sure the output goes to > printk_emergency() (so the output hits the uart right away). > - enable lockdep and check what explodes. thanks a lot for your suggestions. Testing on 5.9 will happen soon (custom hardware, you know the dance...). I'm looking right now into implementing >write_atomic() for the i.mx8. What we found so far: The root of the problem seems to be in ci_hdrc_remove_device(), called by ci_hdrc_imx_shutdown(). With ci_hdrc_imx_driver.shutdown being a no-op, reboot works fine. Peng Fan, does this ring a bell? The issue seems to be timing sensitive, enabling lockdep makes the problem go away. :-( -- Thanks, //richard
