Hi, >>> But with DCACHE ON, the USB Stick is not found - maybe a timing problem: >>> >>> TOP9000> dc off >>> Data (writethrough) Cache is OFF >>> TOP9000> usb reset >>> (Re)start USB... >>> USB: scanning bus for devices... 2 USB Device(s) found >>> >>> scanning bus for storage devices... 1 Storage Device(s) found >>> >>> TOP9000> dc on >>> Data (writethrough) Cache is ON >>> TOP9000> usb reset >>> (Re)start USB... >>> USB: scanning bus for devices... ERROR: CTL:TIMEOUT >>> 2 USB Device(s) found >>> >>> scanning bus for storage devices... 0 Storage Device(s) found >>> >>> TOP9000> >>> >>> >>> Reinhard >> If the USB controller uses DMA, then the DCache issue probably has to do >> with making sure to flush the (relevant lines of) cache before >> memory-to-device DMAs and to invalidate the (again, relevant lines of) >> cache after device-to-memory DMAs. > > Correct. Note that the EHCI driver already supports such a mode with d-cache > enabled. You need to set CONFIG_EHCI_DCACHE to enable these cache handling > functions.
AT91 uses OHCI. As far as I can tell there is no cache code in it. And I am not sure whether the USB RAM is cache inhibited. Do any other architectures work with DCACHE and OHCI? Best Regards, Reinhard _______________________________________________ U-Boot mailing list U-Boot@lists.denx.de http://lists.denx.de/mailman/listinfo/u-boot