Hi Jean, with these two patches the code in i2c-i801.c looks really good. But there is an issue with the reproducer. > I noticed this bug in a QEMU x86_64 q35 VM booted with OVMF. OVMF > doesn't inititialize the SMBus master. After 1s of SMBus inactivity > autosuspend disables the SMBus master. To reproduce please note QEMU's > ICH9 SMBus emulation does not handle interrupts and it's necessary > to pass the parameter disable_features=0x10 to the i2c_i801 driver. Since commit a9c8088c7988e "i2c: i801: Don't restore config registers on runtime PM" the reproducer doesn't work anymore. This is because commit a9c8088c7988e works as intended and the pm->runtime_* callbacks no longer call i801_suspend() and i801_resume(). But there is more. With the SMBus master in runtime suspended state the direct-complete mechanism skips the calls to the pm->suspend and pm->resume callbacks on system suspend/resume. I am convinced in nearly all cases this disables the fix from commit a5aaea37858fb "i2c-i801: Restore the device state before leaving". At the moment I see two ways to fix this problem. One way is to revert a9c8088c7988e "i2c: i801: Don't restore config registers on runtime PM", the other is to set the driver flag DPM_FLAG_NO_DIRECT_COMPLETE in i801_probe(). I tested both, but I can't decide which way is better. With best regards, Volker
