Re: [PATCHv3] driver: serial: prevent UART console idle on suspend while using "no_console_suspend"

From: Kevin Hilman
Date: Fri Apr 05 2013 - 13:40:44 EST


Sourav Poddar <sourav.poddar@xxxxxx> writes:

> With dt boot, uart wakeup after suspend is non functional while using
> "no_console_suspend" in the bootargs. With "no_console_suspend" used, we
> should prevent the runtime suspend of the uart port which is getting used
> as an console.
>
> Cc: Santosh Shilimkar<santosh.shilimkar@xxxxxx>
> Cc: Felipe Balbi<balbi@xxxxxx>
> Cc: Rajendra nayak<rnayak@xxxxxx>
> Tested on omap5430evm, omap4430sdp.
>
> Signed-off-by: Sourav Poddar <sourav.poddar@xxxxxx>

Rather than make these special checks inside the driver's runtime PM
callbacks, you should just disable runtime PM (pm_runtime_disable())

Then, this should be broken into 2 patches.

1) serial core: add the '->is_console' flag. (nit on naming: don't call
it port_is_console, since the struct is already a uart_port)

2) In the OMAP UART driver's ->prepare callback, check the is_console flag
and pm_runtime_disable() accordingly (then pm_runtime_enable() in
the drivers's ->complete callback.

Kevin
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