On Mon, Sep 05, 2016 at 05:39:27PM +0200, Arnd Bergmann wrote: > On Friday, September 2, 2016 5:16:31 PM CEST Leo Li wrote: > > > > Can we use the firmware or bootloader information to provide the > > default dma-mapping attributes for devices that doesn't have an > > of_node pointer or ACPI data? This will at least restore what we had > > previously provided . I'm concerned that changing all the drivers > > that are creating child device will be a big effort. Like I mentioned > > in another thread, there are many instances of platform_device_add() > > under the drivers/ directory. > > Fortunately, there are not too many drivers that call platform_device_add > *and* try to set up a dma mask for the child device: > > git grep -wl dma_mask drivers | xargs grep -wl 'platform_device_\(add\|register\)' > > drivers/base/platform.c > drivers/bcma/main.c > drivers/eisa/virtual_root.c > drivers/mfd/mfd-core.c > drivers/mfd/omap-usb-host.c > drivers/misc/mic/card/mic_x100.c > drivers/platform/goldfish/pdev_bus.c > drivers/ssb/main.c > drivers/usb/chipidea/core.c > drivers/usb/dwc3/dwc3-exynos.c > drivers/usb/dwc3/host.c > drivers/usb/gadget/udc/bdc/bdc_pci.c > drivers/usb/host/bcma-hcd.c > drivers/usb/host/fsl-mph-dr-of.c > drivers/usb/host/ssb-hcd.c > drivers/usb/misc/ftdi-elan.c > drivers/usb/musb/blackfin.c > drivers/usb/musb/musb_dsps.c > drivers/usb/musb/omap2430.c > drivers/usb/musb/ux500.c > > Most of these are probably never used with any nonstandard > DMA settings (IOMMU, cache coherency, offset, ...). > > One thing we could possibly do is to go through these and > replace the hardcoded dma mask setup with of_dma_configure() > in all cases in which we actually use DT for probing, which > should cover the interesting cases. > One case I am going to work is to let USB chipidea driver support iommu, the chipidea core device is no of_node, and created by platform_add_device on the runtime. Using of_dma_configure with parent of_node is a solution from my point, like [1]. https://lkml.org/lkml/2016/2/22/7 -- 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
