Hi Kevin,
On Tuesday 23 April 2013 12:06 AM, Kevin Hilman wrote:
Grygorii Strashko<grygorii.strashko@xxxxxx> 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.poddar@xxxxxx>
---
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.
Yes, got the point.
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.
Ok. Will adapt the next version inline with the above suggestions.
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
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