On Sun, 2026-05-31 at 23:49 +0200, Danilo Krummrich wrote: > On Sun May 31, 2026 at 9:42 PM CEST, Markus Probst wrote: > > I just noticed, is it even possible to use SRCU here? Currently the mutex > > not > > only ensures that no drvdata access happens after drvdata drop, but also > > that > > the receive_buf waits for the probe to complete, as the drvdata hasn't been > > initialized yet. > > Yeah, if you drop the completion, you need the mutex. Is the performance impact on an mutex or on srcu + completion higher?
> > (In case it wasn't discussed in previous versions already, there is also the > option to just attach separate private data to the receive callback, which > would > avoid this synchonization problem in the first place. > > You could have serdev::Device<Core>::open(), which takes its own private data > and a corresponding close(), this way you'd allow drivers to control whether > they want the serial line "open" or not. You just need to make sure it is > closed > eventually.) This would add complexity with types, as we need to ensure that write, set_baudrate, set_parity etc. does not run when closed. > > That said, I don't know what turns out to be the better approach. And maybe it > simply isn't something this initial series has to tackle? I think your driver > does not implement the receive callback? The initial driver with only leds: no. That changes once the driver also takes care of hwmon (ADC sensor and fan failure) and input (power button and possibly other buttons). Thanks - Markus Probst
signature.asc
Description: This is a digitally signed message part
