Hi Rob, On Thursday 29 January 2015 10:49:38 Rob Herring wrote: > On Wed, Jan 28, 2015 at 5:32 PM, Laurent Pinchart wrote: > > On Wednesday 28 January 2015 13:32:19 Will Deacon wrote: > >> On Wed, Jan 28, 2015 at 01:15:10PM +0000, Laurent Pinchart wrote: > >>> On Wednesday 28 January 2015 12:29:42 Will Deacon wrote: > >>>> On Wed, Jan 28, 2015 at 12:23:03PM +0000, Laurent Pinchart wrote: > >>>>> On Wednesday 28 January 2015 11:33:00 Will Deacon wrote: > >>>>>> On Mon, Jan 26, 2015 at 06:49:01PM +0000, Murali Karicheri wrote: > >>>>>> On 01/25/2015 08:32 AM, Laurent Pinchart wrote: > >>>>>>>> On Friday 23 January 2015 17:32:34 Murali Karicheri wrote: > >>>>>>>>> Function of_iommu_configure() is called from of_dma_configure() > >>>>>>>>> to setup iommu ops using DT property. This API is currently used > >>>>>>>>> for platform devices for which DMA configuration (including iommu > >>>>>>>>> ops) may come from device's parent. To extend this functionality > >>>>>>>>> for PCI devices, this API need to take a parent node ptr as an > >>>>>>>>> argument instead of assuming device's parent. This is needed since > >>>>>>>>> for PCI, the dma configuration may be defined in the DT node of > >>>>>>>>> the root bus bridge's parent device. Currently only dma-range is > >>>>>>>>> used for PCI and iommu is not supported. So return error if the > >>>>>>>>> device is PCI. > > [...] > > >>> If I understand Murali's patch set right (please correct me if that's > >>> not the case) the PCI code walks up the DT nodes hierarchy to the > >>> parent node that contains the iommus attribute and passes a pointer to > >>> that node to this function. It's thus a PCI-specific solution. As a > >>> temporary hack that's OK I suppose, but if implementing it right > >>> straight away isn't difficult that would be better. > >> > >> It looks to me like the code walks the PCI topology to get the DT node > >> for the host controller, and passes *that* to of_dma_configure. That > >> sounds like the right thing to do to me, especially since the PCI > >> topology is likely not encoded in the device-tree. So actually, it is > >> passing the first parent node afaict. > > > > Indeed, that's right. I forgot for a moment that we have non-DT devices > > ;-) > > > > Acked-by: Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx> > > > > Murali, nitpicking a bit, shouldn't the iommu_np parameter be renamed ? It > > points to the node containing the iommus parameter, not to the iommu node, > > so the current name is slightly confusing. A brief kerneldoc above the > > function would also help. This can be the subject of a separate patch. > > It was more confusing having np and node within the function. Agreed. How about master_np or iommu_master_np ? The latter might be a bit long. -- Regards, Laurent Pinchart -- 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
