RE: [RFC 8/9] drivers: of: call iommu_bus_add_dev after iommu_configure_ops

["Sricharan" <sricharan-sgV2jX0FEOL9JmXXK+q4OQ@public.gmane.org>]

Hi Robin,

>On 25/04/16 16:58, Sricharan R wrote:
>> Now that the device's iommu ops are configured at probe time,
>> the device has to be added to the iommu late.
>>
>> Signed-off-by: Sricharan R <sricharan-sgV2jX0FEOL9JmXXK+q4OQ@public.gmane.org>
>> ---
>>   drivers/of/device.c | 4 ++++
>>   1 file changed, 4 insertions(+)
>>
>> diff --git a/drivers/of/device.c b/drivers/of/device.c
>> index 57a5f2d..722115c 100644
>> --- a/drivers/of/device.c
>> +++ b/drivers/of/device.c
>> @@ -6,6 +6,7 @@
>>   #include <linux/of_iommu.h>
>>   #include <linux/dma-mapping.h>
>>   #include <linux/init.h>
>> +#include <linux/iommu.h>
>>   #include <linux/module.h>
>>   #include <linux/mod_devicetable.h>
>>   #include <linux/slab.h>
>> @@ -154,6 +155,9 @@ int of_dma_configure_ops(struct device *dev, struct device_node *np)
>>   	dev_dbg(dev, "device is%sbehind an iommu\n",
>>   		iommu ? " " : " not ");
>>
>> +	if (iommu)
>> +		iommu_bus_add_dev(dev);
>
>This (in conjunction with the previous patch) seems unnecessarily
>convoluted - if of_iommu_configure() has found some iommu_ops for a
>device, why not just call .add_device() directly there and then? There
>are already systems that could warrant having two different IOMMU
>drivers active simultaneously (but thankfully don't _need_ to), so
>trying to escape from per-bus IOMMU ops makes more sense than
>entrenching the horrible notion of "the" IOMMU on "the" platform bus any
>further.
>
  Ok, agree on this. This will remove the addition of that api in previous
  patch as well. Will change this.

Regards,
 Sricharan