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Subject: Re: [PATCH 4/5] mmc: sdhci-omap: Add OMAP SDHCI driver
To: Kishon Vijay Abraham I <kishon@ti.com>,
        Ulf Hansson <ulf.hansson@linaro.org>
Cc: Rob Herring <robh+dt@kernel.org>, Tony Lindgren <tony@atomide.com>,
        Sekhar Nori <nsekhar@ti.com>, Russell King <linux@armlinux.org.uk>,
        Ravikumar Kattekola <rk@ti.com>, linux-mmc@vger.kernel.org,
        devicetree@vger.kernel.org, linux-kernel@vger.kernel.org,
        linux-omap@vger.kernel.org, linux-arm-kernel@lists.infradead.org
References: <20170821074132.4622-1-kishon@ti.com>
 <20170821074132.4622-5-kishon@ti.com>
 <4f0a7225-1843-b353-1a2a-9adcb49554d3@intel.com>
 <c7972f00-ef62-1736-822f-ebf6822b6d33@ti.com>
From: Adrian Hunter <adrian.hunter@intel.com>
Organization: Intel Finland Oy, Registered Address: PL 281, 00181 Helsinki,
 Business Identity Code: 0357606 - 4, Domiciled in Helsinki
Message-ID: <dfe1b4e2-bcb5-c969-efe6-7cddd0eb0bf9@intel.com>
Date: Thu, 31 Aug 2017 16:02:23 +0300
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On 30/08/17 16:53, Kishon Vijay Abraham I wrote:
> On Monday 28 August 2017 02:36 PM, Adrian Hunter wrote:
>> On 21/08/17 10:41, Kishon Vijay Abraham I wrote:
>>> +
>>> +static void sdhci_omap_set_clock(struct sdhci_host *host, unsigned int clock)
>>> +{
>>> +	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
>>> +	struct sdhci_omap_host *omap_host = sdhci_pltfm_priv(pltfm_host);
>>> +	unsigned long clkdiv;
>>> +
>>> +	if (!clock)
>>> +		return;
>>
>> Are you sure you don't want to stop the clock.
> 
> There is never a case where the MMC core sends a request to stop the clock.
> Maybe this check is not required at all.

It does when voltage switching e.g. mmc_set_uhs_voltage(), but host drivers
should support the possibility anyway.