Messages in this thread | | | Date | Mon, 22 Apr 2013 17:48:55 +0300 | From | Grygorii Strashko <> | Subject | Re: [PATCHv2 2/5] driver: serial: omap: prevent runtime PM for "no_console_suspend" |
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On 04/22/2013 04:43 PM, Sourav Poddar wrote: > The driver manages "no_console_suspend" by preventing runtime PM > during the suspend path, which forces the console UART to stay awake. > > Signed-off-by: Sourav Poddar <sourav.poddar@ti.com> > --- > drivers/tty/serial/omap-serial.c | 5 ++++- > 1 files changed, 4 insertions(+), 1 deletions(-) > > diff --git a/drivers/tty/serial/omap-serial.c b/drivers/tty/serial/omap-serial.c > index 08332f3..640b14e 100644 > --- a/drivers/tty/serial/omap-serial.c > +++ b/drivers/tty/serial/omap-serial.c > @@ -1582,7 +1582,7 @@ static int serial_omap_runtime_suspend(struct device *dev) > struct uart_omap_port *up = dev_get_drvdata(dev); > struct omap_uart_port_info *pdata = dev->platform_data; > > - if (!up) > + if (!up || (!console_suspend_enabled && uart_console(&up->port))) > return -EINVAL; Hi Sourav, No ) You will block Runtime PM for console UART forever, but instead it need to be blocked only during suspend - autosuspend should continue working. But this will be not easy, again, - because System suspend isn't synchronized with Runtime PM (I mean, serial_omap_suspend/resume() may be called from one thread and serial_omap_runtime_suspend/resume() from another at same time). And now, serial_omap_suspend() callback is the only one place where you can detect that system is going to sleep.
Personally, i don't believe in such approach (my experiences from K3.4 said me that there will be more problems than benefits).
And, I like combination of "no_console_suspend" in bootargs + "ti,no_idle_on_suspend" for console UART in DT, because 1) it's debug option and 2) until smth. will be decided about OMAP OCP Bus it can be used.
It's just my opinion.
Regards, -grygorii > > if (!pdata) > @@ -1614,6 +1614,9 @@ static int serial_omap_runtime_resume(struct device *dev) > > int loss_cnt = serial_omap_get_context_loss_count(up); > > + if (!console_suspend_enabled && uart_console(&up->port)) > + return -EINVAL; > + > if (loss_cnt < 0) { > dev_err(dev, "serial_omap_get_context_loss_count failed : %d\n", > loss_cnt);
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