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Date: Tue, 09 Sep 2014 15:03:53 -0500
From: Timur Tabi <timur@tabi.org>
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To: Nicolin Chen <nicoleotsuka@gmail.com>
Subject: Re: [PATCH V1] ASoC: fsl_ssi: refine ipg clock usage in this module
References: <e5a50d8bfde3aea5fcd092118da5aea4072c7e2f.1410254125.git.shengjiu.wang@freescale.com>
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 <20140909195928.GA5224@Asurada>
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Cc: Shengjiu Wang <shengjiu.wang@freescale.com>, alsa-devel@alsa-project.org,
 tiwai@suse.de, linux-kernel@vger.kernel.org, broonie@kernel.org,
 lgirdwood@gmail.com, perex@perex.cz, Li.Xiubo@freescale.com,
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On 09/09/2014 02:59 PM, Nicolin Chen wrote:
> +	/*
> +	 * 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;

According to Mark, NULL is a valid clock, so this should be instead:

	ssi_private->clk = PTR_ERR(-EINVAL);

although that doesn't sit well with me.