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

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Message-ID: <20090804180044.GH8601@sortiz.org>
Date:	Tue, 4 Aug 2009 20:00:46 +0200
From:	Samuel Ortiz <sameo@...ux.intel.com>
To:	Amit Kucheria <amit.kucheria@...durent.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

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 ?

Cheers,
Samuel.


> +		if (!(mask & TRITON_WAKEUP12_SCRIPT))
> +			printk(KERN_WARNING
> +			       "TWL4030: Wakeup script not yet loaded. Might lead to boot failure on some boards\n");
>  		err |= config_sleep_sequence(address);
> +	}
>  
>  	return err;
>  }
> -- 
> 1.6.3.3
> 

-- 
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http://oss.intel.com/
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