On Tue, Aug 21, 2012 at 04:35:26PM +0530, Shilimkar, Santosh wrote:

On Tue, Aug 21, 2012 at 4:27 PM, Felipe Balbi [off-list ref] wrote:

quoted

On Tue, Aug 21, 2012 at 04:12:11PM +0530, Shilimkar, Santosh wrote:

quoted

On Tue, Aug 21, 2012 at 2:45 PM, Felipe Balbi [off-list ref] wrote:

quoted

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 <redacted>
---
 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.

will do, cheers

-- 
balbi
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