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Date: Wed, 10 Sep 2014 18:01:42 +0800
From: Shengjiu Wang <shengjiu.wang@freescale.com>
To: Nicolin Chen <nicoleotsuka@gmail.com>
Subject: Re: [PATCH V1] ASoC: fsl_ssi: refine ipg clock usage in this module
Message-ID: <20140910100141.GA17326@audiosh1>
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Cc: alsa-devel@alsa-project.org, lgirdwood@gmail.com, tiwai@suse.de,
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On Tue, Sep 09, 2014 at 12:59:29PM -0700, Nicolin Chen wrote:
> On Tue, Sep 09, 2014 at 02:37:42PM -0500, Timur Tabi wrote:
> > On 09/09/2014 01:38 PM, Nicolin Chen wrote:
> > >make sure to have the call for imx only because it seems that
> > >the other platforms do not depend on the clock.
> > 
> > Although I doubt anyone will every add support for clocks to PowerPC "side"
> > of this driver, I would prefer to avoid IMX-specific changes. Instead, the
> > code should check if a clock is available.  That's why I suggested this
> > change:
> > 
> > -	if (ssi_private->soc->imx)
> > +	if (!IS_ERR(ssi_private->clk))
> 
> Hmm.... I think the following change may be better?
> 
> probe() {
> 	....
> +	/*
> +	 * Initially mark the clock to NULL for all platforms so that later
> +	 * clk_prepare_enable() will ignore and return 0 for non-clock cases.
> +	 */
> +	ssi_private->clk = NULL;
> 	.....
> 	fsl_ssi_imx_probe();
> }
ssi_private is initialized to zero in beginning of probe. I think no need to
add this change here.

wang shengjiu
> 
> In this way, all platforms, not confined to imx any more, will be able
> to call clk_prepare_enable(). Then we don't need an extra platform check
> before calling it.