On Tue, Sep 16, 2014 at 09:02:11PM +0100, Tanmay Inamdar wrote: > On Fri, Sep 12, 2014 at 2:18 AM, Liviu Dudau <Liviu.Dudau@xxxxxxx> wrote: > > On Thu, Sep 11, 2014 at 11:57:43PM +0100, Tanmay Inamdar wrote: > >> This patch adds the AppliedMicro X-Gene SOC PCIe host controller driver. > >> X-Gene PCIe controller supports maximum up to 8 lanes and GEN3 speed. > >> X-Gene SOC supports maximum 5 PCIe ports. > >> > >> Signed-off-by: Tanmay Inamdar <tinamdar@xxxxxxx> > > > > It looks good to me now. You can add if you care: > > > > Reviewed-by: Liviu Dudau <Liviu.Dudau@xxxxxxx> > > I will have to send another version of patch as I forgot to add > 'dma-coherent' in device tree entry. > > Secondly I see that setting 'dma-coherent' in device tree node sets > coherent_dma_ops for the root bus but for the endpoint another 'dev' > gets assigned. This causes endpoint to use non-coherent dma apis > causing failure in dma operations. For PCIe, setting dma-coherent in the DT nodes wouldn't have any effect yet. We have of_dma_configure() being called for platform devices but it won't work for PCIe which are probed at run-time (nor for AMBA which require an additional patch). So for arm64 currently we have some hooks in dma-mapping.c to intercept when a device is added to a bus. What I need to do though is check recursively whether the parent (bus) had the 'dma-coherent' property (pointed out by Jon). I think something like this would do (not tested): diff --git a/arch/arm64/mm/dma-mapping.c b/arch/arm64/mm/dma-mapping.c index 4164c5ace9f8..638475378f94 100644 --- a/arch/arm64/mm/dma-mapping.c +++ b/arch/arm64/mm/dma-mapping.c @@ -316,7 +316,7 @@ static int dma_bus_notifier(struct notifier_block *nb, if (event != BUS_NOTIFY_ADD_DEVICE) return NOTIFY_DONE; - if (of_property_read_bool(dev->of_node, "dma-coherent")) + if (of_dma_is_coherent(dev->of_node)) set_dma_ops(dev, &coherent_swiotlb_dma_ops); return NOTIFY_OK; After this, we need to a bus notifier for PCIe as well. Since I don't think we have an of_node for a PCI device, we would need to check recursively on the parent device rather than the parent node until we find an OF node with the 'dma-coherent' property. -- Catalin -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
