* Andy Shevchenko <andy.shevche...@gmail.com> [200602 08:33]: > On Tue, Jun 2, 2020 at 11:09 AM Johan Hovold <jo...@kernel.org> wrote: > > On Mon, Jun 01, 2020 at 05:18:13PM -0700, Tony Lindgren wrote: > > ... > > > There's shouldn't be anything fundamental preventing you from adding the > > missing resume calls to the mctrl paths even if it may require reworking > > (and fixing) the whole RPM implementation (which would be a good thing > > of course). > > Yes, for serial core I have long standing patch series to implement > RPM (more or less?) properly.
Yeah let's try after the merge window. Not sure what else to do with the fix though. We currently have 8250_port.c not really aware of the hardare state for PM runtime at least for the hang-up path. > However, OMAP is a beast which prevents us to go due to a big hack > called pm_runtime_irq_safe(). > Tony is aware of this and I think the above is somehow related to removal of > it. Now that we can detach and reattach the kernel serial console, there should not be any need for pm_runtime_irq_safe() anymore :) And the UART wake-up from deeper idle states can only happen with help of external hardware like GPIO controller or pinctrl controller. And for the always-on wake-up interrupt controllers we have the Linux generic wakeirqs to wake-up serial device on events. So I think the way to procedd with pm_runtime_irq_safe() removal for serial drivers is to block serial PM runtime unless we have a wakeirq configured for omaps in devicetree. In the worst case the regression is that PM runtime for serial won't work unless properly configured. And the UART wakeup latency will be a bit longer compared to pm_runtime_irq_safe() naturally. > But I completely agree that the goal is to get better runtime PM > implementation over all. Yes agreed. Regards, Tony
