Date: Sun, 8 Feb 2015 14:58:28 +1030 From: "O'Connor, Daniel" <darius@dons.net.au> To: Hans Petter Selasky <hps@selasky.org> Cc: FreeBSD Hackers <freebsd-hackers@freebsd.org> Subject: Re: Two drivers sharing a single PCI device Message-ID: <B201EE1A-792F-46B9-AF8B-004D27AC5C45@dons.net.au> In-Reply-To: <54D5AB87.9050309@selasky.org> References: <643918BB-810C-4FB2-AE1A-C4CDA6C8A661@dons.net.au> <54D4ABA6.805@selasky.org> <F6DF0E64-EFFC-4CC9-8375-85F88AE0941F@dons.net.au> <54D5AB87.9050309@selasky.org>
next in thread | previous in thread | raw e-mail | index | archive | help
> On 7 Feb 2015, at 16:37, Hans Petter Selasky <hps@selasky.org> wrote: >>> You possibly want "D_TRACKCLOSE" in d_flags in your cdevsw. >>=20 >>> What's the advantage of using the debug port over the regular EHCI = USB interface? >>=20 >> I don't think that would help. It is supposed to be (largely) = separate from the regular EHCI controller - it has it's own register set = and it can steal the debug port from the regular controller so it = doesn't appear occupied (although there is a bit of messing around on = port reset). >>=20 >> The advantage is that it runs separately to the EHCI interface and it = is quite simple to talk to, there is more information in appendix C of = the USB 2 spec (usb_20.pdf). >>=20 >=20 > Hi, >=20 > You know about "sys/boot/usb" ? If you could integrate the USB debug = port to use the kernel USB stack HOST API, only limited to BULK, CONTROL = and INTERRUPT, then we could easily use it there aswell. The EHCI debug = port functions very much resemble those found in = "sys/dev/usb/controller/dwc_otg*" for example. Hmm I am not really sure what it's for.. Is it for the loader? Basically I would like to be able to run a console and GDB port over = USB, although I think it won't be quite as good as a 'real' serial one = because it will have to start later (when the PCI bus is up). FWIW I did get my driver and EHCI to attach at the same time - I = iterated over pci_devq and allocated my own softc in MOD_LOAD. The next = part is trying to get the EHCI controller from stealing back the debug = port - it gets lost on reset I think so I need to work out how to tell = it not to touch it (if possible). -- Daniel O'Connor "The nice thing about standards is that there are so many of them to choose from." -- Andrew Tanenbaum GPG Fingerprint - 5596 B766 97C0 0E94 4347 295E E593 DC20 7B3F CE8C
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?B201EE1A-792F-46B9-AF8B-004D27AC5C45>