On Thu, 12 Dec 2013 09:57:05 +0200, Hiroshi Doyu <hdoyu@xxxxxxxxxx> wrote: > IOMMU devices on the bus need to be poplulated first, then iommu > master devices are done later. > > With CONFIG_OF_IOMMU, "iommus=" DT binding would be used to identify > whether a device can be an iommu msater or not. If a device can, we'll > defer to populate that device till an iommu device is populated. Then, > those deferred iommu master devices are populated and configured with > help of the already populated iommu device. > > Signed-off-by: Hiroshi Doyu <hdoyu@xxxxxxxxxx> > Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> > --- > This is related to the following discussion: > [RFC PATCH] Documentation: devicetree: add description for generic bus properties > http://lists.infradead.org/pipermail/linux-arm-kernel/2013-November/215042.html > > v6: > Spinned off only driver core part from: > [PATCHv5 2/9] driver/core: populate devices in order for IOMMUs > > v5: > Use "iommus=" binding instread of arm,smmu's "#stream-id-cells". > > v4: > This is newly added, and the successor of the following RFC: > [RFC][PATCHv3+ 1/2] driver/core: Add of_iommu_attach() > http://lists.linuxfoundation.org/pipermail/iommu/2013-November/006914.html > > Signed-off-by: Hiroshi Doyu <hdoyu@xxxxxxxxxx> > --- > drivers/base/dd.c | 5 +++++ > 1 file changed, 5 insertions(+) > > diff --git a/drivers/base/dd.c b/drivers/base/dd.c > index 0605176..0605f52 100644 > --- a/drivers/base/dd.c > +++ b/drivers/base/dd.c > @@ -25,6 +25,7 @@ > #include <linux/async.h> > #include <linux/pm_runtime.h> > #include <linux/pinctrl/devinfo.h> > +#include <linux/of_iommu.h> > > #include "base.h" > #include "power/power.h" > @@ -273,6 +274,10 @@ static int really_probe(struct device *dev, struct device_driver *drv) > > dev->driver = drv; > > + ret = of_iommu_attach(dev); > + if (ret) > + goto probe_failed; > + As discussed before, I really don't think hooking in to dd.c is the right thing to do here, and certainly not as a device tree specific function. ACPI or PCI described devices may have the same constraints and those won't have DT descriptions. I don't think we've got a good solution yet for this problem. :-( g. -- To unsubscribe from this list: send the line "unsubscribe linux-tegra" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
