Hi folks, > I don't think we are consistent in any way. PowerPC sets up a 32 bit > DMA mask for all devices during DT probe from arch code, while the > common code sets up coherent_dma_mask but not dma_mask, except > for AMBA devices, which also get the 32 bit mask. > > The MIPS Octeon and PowerPC PS3 EHCI backends set up the dma mask > because platform code doesn't do it for them, but both drivers are > not using DT. The Xilinx and PPC-OF EHCI back-end do not set it up, > because on microblaze and powerpc it does come from the platform > code. > > I think it's a horrible mess and if anyone has an idea of what the > right solution is, we should probably implement that, but from what > I see here, setting a 32-bit dma mask unless there is already one > is a reasonable choice. I also ran into this issue with loading the dwc2 driver from OF recently, and stumbled upon this (unfinished) patch that sets up the dma_mask using a "dma-mask" property in the DT, which looks like the proper way to do this to me: https://lists.ozlabs.org/pipermail/devicetree-discuss/2012-March/013172.html https://lists.ozlabs.org/pipermail/devicetree-discuss/2012-March/013179.html https://lists.ozlabs.org/pipermail/devicetree-discuss/2012-March/013293.html http://lists.infradead.org/pipermail/linux-arm-kernel/2012-December/135991.html It's probably not up to you guys to implement this, but perhaps it helps to get some perspective? Gr. Matthijs -- 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
