On 5 June 2015 at 04:59, Stephen Warren [off-list ref] wrote:

On 05/29/2015 03:06 PM, Eric Anholt wrote:

quoted

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.

quoted

diff --git a/drivers/mmc/host/sdhci-bcm2835.c b/drivers/mmc/host/sdhci-bcm2835.c

quoted

+     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
Uffe