On Dec 18, 2012, at 1:22 AM, Hans Petter Selasky wrote: > On Tuesday 18 December 2012 08:49:31 Andrew Turner wrote: >> Hello, >> >> Oleksandr and myself have been looking into why when we enable the >> write-back cache on the PandaBoard there are kernel panics with USB. We >> have tracked it down to an issue appending the ehci_qh_t to the list at >> the end of ehci_setup_standard_chain(). >> >> I have a patch at [1] that allows me to run sha256 on a 40MB file over >> NSF using the built in smsc USB ethernet chip. The problem is I have >> had to place a call to DELAY before EHCI_APPEND_QH. This is obviously >> not the correct solution. >> >> Is anyone able to help me narrow down what is missing? It appears to be >> a missing cache invalidate or flush somewhere but I haven't been able >> to track down what cache function the DELAY is working around. >> >> Andrew >> >> [1] http://fubar.geek.nz/files/freebsd/ehci_4.diff > > Hi, > > Can you dump the DMA tag belonging to the QH via and check wether it is > mapped > coherent or not. Thes QH- and TD- structures should not be cache mapped. Else > cache has not been disabled on those pages.
busdma doesn't work that way. The coherent flag is just a hint.... Warner > qh->page_cache->tag > > --HPS > _______________________________________________ > [email protected] mailing list > http://lists.freebsd.org/mailman/listinfo/freebsd-usb > To unsubscribe, send any mail to "[email protected]" _______________________________________________ [email protected] mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-usb To unsubscribe, send any mail to "[email protected]"
