On Thu, Oct 03, 2024 at 01:10:47PM -0700, Doug Anderson wrote: > On Tue, Oct 1, 2024 at 5:51 AM Johan Hovold <johan+linaro@xxxxxxxxxx> wrote: > > @@ -1179,6 +1179,11 @@ static int qcom_geni_serial_startup(struct uart_port *uport) > > if (ret) > > return ret; > > } > > + > > + uart_port_lock_irq(uport); > > + qcom_geni_serial_start_rx(uport); > > + uart_port_unlock_irq(uport); > > I _think_ you don't need the locking here. The documentation for the > "startup" callback say: > > * Interrupts: globally disabled. Heh, yeah, that comment dates back to 2002 and probably wasn't even correct back then. This function is called with the port mutex held (and interrupts enabled), and I need to take the port lock to serialise against the console code. > Other than that, this looks reasonable to me. I seem to recall > previous discussions where _someone_ was relying on the > qcom_geni_serial_start_rx() at the end of termios for some reason > (which always felt like a bad design), but I can't find those old > discussions. I suspect that the fact that you've added the start_rx in > startup() is what we needed. Yeah, I tried to find a reason for why things were done this way, but it was probably just copied from the vendor driver. The hardware doesn't seem to require stopping rx in set_termios() (and tx is not stopped anyway), which could otherwise have been a reason. Johan
