linux-kernel - Re: [PATCH 2/3] MFD: TWL4030: print warning for out-of-order script loading

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Date:	Mon, 17 Aug 2009 14:43:32 +0300
From:	Amit Kucheria <amit.kucheria@...durent.com>
To:	Samuel Ortiz <sameo@...ux.intel.com>
Cc:	dbrownell@...rs.sourceforge.net, linux-kernel@...r.kernel.org,
	linux-omap@...r.kernel.org
Subject: Re: [PATCH 2/3] MFD: TWL4030: print warning for out-of-order
 script loading

On 09 Aug 04, Samuel Ortiz wrote:
> Hi Amit,
> 
> On Wed, Jul 08, 2009 at 01:49:35PM +0300, Amit Kucheria wrote:
> > When the sleep script is loaded before the wakeup script, there is a
> > chance that the system might go to sleep before the wakeup script
> > loading is completed. This will lead to a system that does not wakeup
> > and has been observed to cause non-booting boards.
> > 
> > Various options were considered to solve this problem, including
> > modification of the core twl4030 power code to be smart enough to
> > reorder the loading of the scripts. But it felt too over-engineered.
> > 
> > Hence this patch just warns the DPS script developer so that they may be
> > reordered in the board-code itself.
> > 
> > Signed-off-by: Amit Kucheria <amit.kucheria@...durent.com>
> > ---
> >  drivers/mfd/twl4030-power.c |   11 +++++++++--
> >  1 files changed, 9 insertions(+), 2 deletions(-)
> > 
> > diff --git a/drivers/mfd/twl4030-power.c b/drivers/mfd/twl4030-power.c
> > index bb9e45f..ef4cc4e 100644
> > --- a/drivers/mfd/twl4030-power.c
> > +++ b/drivers/mfd/twl4030-power.c
> > @@ -315,6 +315,7 @@ static int __init load_triton_script(struct twl4030_script *tscript)
> >  {
> >  	u8 address = triton_next_free_address;
> >  	int err;
> > +	static u8 mask = 0;
> >  
> >  	/* Make sure the script isn't going beyond last valid address */
> >  	if ((address + tscript->size) > (END_OF_SCRIPT-1)) {
> > @@ -331,14 +332,20 @@ static int __init load_triton_script(struct twl4030_script *tscript)
> >  	if (tscript->flags & TRITON_WRST_SCRIPT)
> >  		err |= config_warmreset_sequence(address);
> >  
> > -	if (tscript->flags & TRITON_WAKEUP12_SCRIPT)
> > +	if (tscript->flags & TRITON_WAKEUP12_SCRIPT) {
> >  		err |= config_wakeup12_sequence(address);
> > +		mask |= TRITON_WAKEUP12_SCRIPT;
> > +	}
> >  
> >  	if (tscript->flags & TRITON_WAKEUP3_SCRIPT)
> >  		err |= config_wakeup3_sequence(address);
> >  
> > -	if (tscript->flags & TRITON_SLEEP_SCRIPT)
> > +	if (tscript->flags & TRITON_SLEEP_SCRIPT) {
> Wouldnt something like:
> 
>      if (tscript->flags & (TRITON_SLEEP_SCRIPT | TRITON_WAKEUP12_SCRIPT)) {
> 
> save us from using an additional mask variable and simplify this patch ?
> 

I don't see how this will save the mask variable. What I need to detect
that the SLEEP script is loaded before the WAKEUP script. That should
trigger a warning.

-- 
-------------------------------------------------------------------------
Amit Kucheria,				 Kernel Developer, Verdurent
-------------------------------------------------------------------------
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