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 ? -- balbi
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