Le 21/10/2010 12:11, Reinhard Meyer a écrit : > Hello, > > observation here: > > ICACHE is always ON. No crash with "usb read 21000000 0 1000" > Sorry that I can't reproduce the problem here, not even with 10000 blocks. > (tried a few dozen times) > (ARM926EJS - AT91SAM9XE) > (based on TOT 3ed16071b006dbda65070a4143db74da469f6e30 of 35h ago) > > 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. And I suggest we move this dcache issue to its own discussion thread. Amicalement, -- Albert. _______________________________________________ U-Boot mailing list U-Boot@lists.denx.de http://lists.denx.de/mailman/listinfo/u-boot