Date: Tue, 18 Dec 2012 20:49:31 +1300 From: Andrew Turner <andrew@fubar.geek.nz> To: freebsd-usb@freebsd.org Cc: Oleksandr Tymoshenko <gonzo@freebsd.org> Subject: EHCI on armv6 with Write-Back caches Message-ID: <20121218204931.5322922d@fubar.geek.nz>
next in thread | raw e-mail | index | archive | help
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
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?20121218204931.5322922d>