On Wed, Sep 07, 2016 at 05:24:08PM +0200, Arnd Bergmann wrote: > On Wednesday, September 7, 2016 1:24:07 PM CEST Felipe Balbi wrote: > > > > Hi, > > > > Arnd Bergmann <arnd@xxxxxxxx> writes: > > > > [...] > > > > > Regarding the DMA configuration that you mention in ci_hdrc_add_device(), > > > I think we should replace > > > > > > pdev->dev.dma_mask = dev->dma_mask; > > > pdev->dev.dma_parms = dev->dma_parms; > > > dma_set_coherent_mask(&pdev->dev, dev->coherent_dma_mask); > > > > > > with of_dma_configure(), which has the chance to configure more than > > > just those three, as the dma API might look into different aspects: > > > > > > - iommu specific configuration > > > - cache coherency information > > > - bus type > > > - dma offset > > > - dma_map_ops pointer > > > > > > We try to handle everything in of_dma_configure() at configuration > > > time, and that would be the place to add anything else that we might > > > need in the future. > > > > There are a couple problems with this: > > > > 1) won't work for PCI-based systems. > > > > DWC3 is used in production PCI-based HW and also in Synopsys HAPS DX > > platform (FPGA that appears like a PCI card to host PC) > > Right, I was specifically talking about the code in chipidea here, > which I think is never used on the PCI bus, and how the current > code is broken. We can probably do better than of_dma_configure() > (see below), but it would be an improvement. Chipidea is also used at PCI bus too, see drivers/usb/chipidea/ci_hdrc_pci.c -- Best Regards, Peter Chen -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
