On Tue, Aug 21, 2012 at 4:27 PM, Felipe Balbi <balbi@xxxxxx> wrote: > On Tue, Aug 21, 2012 at 04:12:11PM +0530, Shilimkar, Santosh wrote: >> On Tue, Aug 21, 2012 at 2:45 PM, Felipe Balbi <balbi@xxxxxx> wrote: >> > Everytime we're done using our TTY, we want >> > the pm timer to be reinitilized. By sticking >> > to pm_runtime_pm_autosuspend() we make sure >> > that this will always be the case. >> > >> > Signed-off-by: Felipe Balbi <balbi@xxxxxx> >> > --- >> > drivers/tty/serial/omap-serial.c | 33 ++++++++++++++++++++++----------- >> > 1 file changed, 22 insertions(+), 11 deletions(-) >> > >> > diff --git a/drivers/tty/serial/omap-serial.c b/drivers/tty/serial/omap-serial.c >> > index 6ea24c5..458d77c 100644 >> > --- a/drivers/tty/serial/omap-serial.c >> > +++ b/drivers/tty/serial/omap-serial.c >> > @@ -164,7 +164,8 @@ static void serial_omap_enable_ms(struct uart_port *port) >> > pm_runtime_get_sync(up->dev); >> > up->ier |= UART_IER_MSI; >> > serial_out(up, UART_IER, up->ier); >> > - pm_runtime_put(up->dev); >> > + pm_runtime_mark_last_busy(up->dev); >> > + pm_runtime_put_autosuspend(up->dev); >> > } >> > >> Can you please expand the change-log a bit ? >> Didn't follow the time re-init part completely. > > It's really just a micro-optimization. The thing is: > > if I call pm_runtime_put(), I will not reinitialize the pm timer to > whatever timeout value I used. This means that pm_runtime_put() could > actually execute right away (if timer was about to expire when I called > pm_runtime_put()). While this wouldn't cause any issues, it's better to > reinitialize the timer and make sure if there's another > read/write/set_termios/whatever coming right after this, UART is still > powered up. > > I mean, it's really just trying to avoid context save & restore when > UART is still under heavy usage. > > Does it make sense ? It does. Would be good to add the above description in the change-log. Thanks for clarification. Regars Santosh -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
