Thierry Reding <thierry.reding@xxxxxxxxx> writes: > From: Thierry Reding <treding@xxxxxxxxxx> > > Attach to the device's master interface of the IOMMU at .probe() time. > IOMMU support becomes available via the DMA mapping API interoperation > code, but this explicit attachment is necessary to ensure proper probe > order. > > Signed-off-by: Thierry Reding <treding@xxxxxxxxxx> > --- > drivers/mmc/host/sdhci-tegra.c | 8 ++++++++ > 1 file changed, 8 insertions(+) > > diff --git a/drivers/mmc/host/sdhci-tegra.c b/drivers/mmc/host/sdhci-tegra.c > index 33100d10d176..b884614fa4e6 100644 > --- a/drivers/mmc/host/sdhci-tegra.c > +++ b/drivers/mmc/host/sdhci-tegra.c > @@ -15,6 +15,7 @@ > #include <linux/err.h> > #include <linux/module.h> > #include <linux/init.h> > +#include <linux/iommu.h> > #include <linux/platform_device.h> > #include <linux/clk.h> > #include <linux/io.h> > @@ -237,6 +238,11 @@ static int sdhci_tegra_probe(struct platform_device *pdev) > match = of_match_device(sdhci_tegra_dt_match, &pdev->dev); > if (!match) > return -EINVAL; > + > + rc = iommu_attach(&pdev->dev); > + if (rc < 0) > + return rc; > + I thought that, if we consider that ->probe() should include minimal H/W probing so that DMA API call in ->probe() could be deferred after ->probe() and till it's in use actually, like opening a device node. For me this decision(minimal h/w probe) seemed logical but it would add a new restriction. One advantage is that we could still keep all drivers wihtout any IOMMU code if it doesn't call DMA API in ->probe(). > soc_data = match->data; > > host = sdhci_pltfm_init(pdev, soc_data->pdata, 0); > @@ -310,6 +316,8 @@ static int sdhci_tegra_remove(struct platform_device *pdev) > clk_disable_unprepare(pltfm_host->clk); > clk_put(pltfm_host->clk); > > + iommu_detach(&pdev->dev); > + > sdhci_pltfm_free(pdev); > > return 0; -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
