[PATCH v2 2/2] mmc: sdhci-bcm2835: Actually enable the clock

Ulf Hansson ulf.hansson at linaro.org
Fri Jun 5 01:48:20 PDT 2015

On 5 June 2015 at 04:59, Stephen Warren <swarren at wwwdotorg.org> wrote:
> On 05/29/2015 03:06 PM, Eric Anholt wrote:
>> We're currently using a fixed frequency clock specified in the DT, so
>> enabling is a no-op.  However, the RPi firmware-based clocks driver
>> can actually disable unused clocks, so when switching to use it we
>> ended up losing our MMC clock once all devices were probed.
>> diff --git a/drivers/mmc/host/sdhci-bcm2835.c b/drivers/mmc/host/sdhci-bcm2835.c
>> +     ret = clk_prepare_enable(pltfm_host->clk);
>> +     if (ret) {
>> +             dev_err(&pdev->dev, "failed to enable host clk\n");
>> +             goto err;
>> +     }
> Given that pltfm_host is a "struct sdhci_pltfm_host" i.e. a type
> defined/handled by sdhci-pltfm.c , I'm rather surprised that
> sdhci-pltfm.c doesn't do this itself. Wouldn't it make sense for it to
> do so?

We could likely move additional clock management into the sdhci-pltfm.
So we would then remove some duplicated code, but we would potentially
also loose some in flexibility. It's worth an effort to look into.

Please go ahead and have a try. :-)

Kind regards

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