Grygorii Strashko <grygorii.stras...@ti.com> writes: > 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.pod...@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.
Correct. Sourav, as I mentioned when I suggested this approach, it should be done *only* during suspend. > 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. So set an 'is_suspending' flag in ->suspend (it may need to be in ->prepare) and clear it in ->resume (->complete), and check the flag in the ->runtime_supend() callback. It's not uncommon for drivers to have such a flag for various reasons. > 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. No, we need to get rid of ti,no_idle_on_suspend. It's an ugly, OMAP-specific hack (and I'm free to insult it because I introduced it.) Kevin -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
