On Wed, Jan 28, 2015 at 5:32 PM, Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx> wrote: > Hi Will, > > 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. Rob -- 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
