Re: [PATCHv2] arm: mach-omap2: prevent UART console idle on suspendwhile using "no_console_suspend"

[Sourav Poddar]

Hi,
On Tuesday 02 April 2013 07:04 PM, Michael Trimarchi wrote:
> Hi
>
> On 02/04/13 15:28, Sourav Poddar wrote:
> > With dt boot, uart wakeup after suspend is non functional while using
> > "no_console_suspend" in the bootargs. With "no_console_suspend" used, od->flags
> > should be ORed with "OMAP_DEVICE_NO_IDLE_ON_SUSPEND", thereby not allowing the console
> > to idle in the suspend path.
> >
> > Tested on omap5430evm, omap4430sdp.
> >
> > Cc: Santosh Shilimkar<santosh.shilimkar@xxxxxx>
> > Cc: Felipe Balbi<balbi@xxxxxx>
> > Cc: Rajendra nayak<rnayak@xxxxxx>
> > Signed-off-by: Sourav Poddar<sourav.poddar@xxxxxx>
> > ---
> > v1->v2
> > These patches were sent before as a series[1], but realised
> > "core_initcall(omap_serial_early_init)" in serial.c get executed
> > irrespective of dt or non dt boot and it will do most of the stuff
> > for us.
> > As suggested by Kevin Hilman in the previous version, this patch will
> > also prevent creating dependency between omap_device
> > (generic device-independent code) and a specific driver (UART).
> >
> > [1]: http://lkml.org/lkml/2013/3/18/294
> >
> >   arch/arm/mach-omap2/omap_device.c |    5 +++--
> >   arch/arm/mach-omap2/omap_hwmod.h  |    5 +++++
> >   arch/arm/mach-omap2/serial.c      |    4 +++-
> >   3 files changed, 11 insertions(+), 3 deletions(-)
> >
> > diff --git a/arch/arm/mach-omap2/omap_device.c b/arch/arm/mach-omap2/omap_device.c
> > index 381be7a..89be64d 100644
> > --- a/arch/arm/mach-omap2/omap_device.c
> > +++ b/arch/arm/mach-omap2/omap_device.c
> > @@ -170,8 +170,9 @@ static int omap_device_build_from_dt(struct platform_device *pdev)
> >   			r->name = dev_name(&pdev->dev);
> >   	}
> >
> > -	if (of_get_property(node, "ti,no_idle_on_suspend", NULL))
> > -		omap_device_disable_idle_on_suspend(pdev);
> > +	if (oh->flags&  HWMOD_DISABLE_IDLE_ON_SUSPEND ||
> > +		of_get_property(node, "ti,no_idle_on_suspend", NULL))
> > +			omap_device_disable_idle_on_suspend(pdev);
> >
> >   	pdev->dev.pm_domain =&omap_device_pm_domain;
> >
> > diff --git a/arch/arm/mach-omap2/omap_hwmod.h b/arch/arm/mach-omap2/omap_hwmod.h
> > index d43d9b6..50e6145 100644
> > --- a/arch/arm/mach-omap2/omap_hwmod.h
> > +++ b/arch/arm/mach-omap2/omap_hwmod.h
> > @@ -459,6 +459,10 @@ struct omap_hwmod_omap4_prcm {
> >    *     correctly, or this is being abused to deal with some PM latency
> >    *     issues -- but we're currently suffering from a shortage of
> >    *     folks who are able to track these issues down properly.
> > + * HWMOD_DISABLE_IDLE_ON_SUSPEND: don't idle this module on suspend. This is
> > + *     needed for uart controller, which requires its clock not to be cut
> > + *     during suspend while using "no_console_suspend" in bootargs with
> > + *     device tree boot.
> >    */
> >   #define HWMOD_SWSUP_SIDLE			(1<<  0)
> >   #define HWMOD_SWSUP_MSTANDBY			(1<<  1)
> > @@ -471,6 +475,7 @@ struct omap_hwmod_omap4_prcm {
> >   #define HWMOD_16BIT_REG				(1<<  8)
> >   #define HWMOD_EXT_OPT_MAIN_CLK			(1<<  9)
> >   #define HWMOD_BLOCK_WFI				(1<<  10)
> > +#define HWMOD_DISABLE_IDLE_ON_SUSPEND		(1<<  12)
> Just a comment more. Why 12 and not 11?
My Bad. For testing, developed it on an internal tree where 11 was also 
occupied. While
rebasing it on 3.9-rc5, didn't realise 11 is free.
Will fix it in the next version.

Thanks,
Sourav
> Michael
>
> >   /*
> >    * omap_hwmod._int_flags definitions
> > diff --git a/arch/arm/mach-omap2/serial.c b/arch/arm/mach-omap2/serial.c
> > index 8396b5b..adbafbd 100644
> > --- a/arch/arm/mach-omap2/serial.c
> > +++ b/arch/arm/mach-omap2/serial.c
> > @@ -236,8 +236,10 @@ static int __init omap_serial_early_init(void)
> >   					uart_name, uart->num);
> >   			}
> >
> > -			if (cmdline_find_option("no_console_suspend"))
> > +			if (cmdline_find_option("no_console_suspend")) {
> >   				no_console_suspend = true;
> > +				oh->flags |= HWMOD_DISABLE_IDLE_ON_SUSPEND;
> > +			}
> >
> >   			/*
> >   			 * omap-uart can be used for earlyprintk logs
> --
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