Date: Fri, 13 Jul 2012 13:56:57 -0400 From: Arnaud Lacombe <lacombar@gmail.com> To: Warner Losh <imp@bsdimp.com> Cc: FreeBSD Hackers <freebsd-hackers@freebsd.org>, FreeBSD Current <freebsd-current@freebsd.org> Subject: Re: newbus' ivar's limitation.. Message-ID: <CACqU3MW%2BBjXu%2B2sAgbtc%2Bx-Mc4heowr9Bi6LAfFR5QYsMVf2Nw@mail.gmail.com> In-Reply-To: <73F3FBC9-337C-4F61-9470-5173D6DAE56B@bsdimp.com> References: <CACqU3MVh6shncm2Vtqj9oe_HxowWscCZ1eJf0q2F%2B=t_xKKBfQ@mail.gmail.com> <31A0DCE7-3B93-41BC-805A-E0B163892112@bsdimp.com> <CACqU3MVy65ck%2Bb8TKXwfXnBV9iuFzj%2ButRBH4Ecg6XDz3Vg5kQ@mail.gmail.com> <5C18109D-E7A8-4868-BEA9-26B63360BB24@bsdimp.com> <CACqU3MUcbozpyqRLUS91p-%2BXANsisLoHzYpbQ8KjCr02=kMHYg@mail.gmail.com> <8048FFC5-6952-49FC-849D-EA1A5675ACBE@bsdimp.com> <CACqU3MVVDSo8fNmCcCm0dyq6skOf%2BJ_9bUWmxpBi137FD=efyg@mail.gmail.com> <CACqU3MVZmuavxcLZ8LGqP5Ze0yW4bkd5NfSFUfUK_Q6wbzDs8Q@mail.gmail.com> <73F3FBC9-337C-4F61-9470-5173D6DAE56B@bsdimp.com>
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Hi, On Thu, Jul 12, 2012 at 1:20 AM, Warner Losh <imp@bsdimp.com> wrote: > [..] > Honestly, though, I think you'll be more pissed when you find out that the N:1 interface that you want is being done in the wrong domain. But I've been wrong before and look forward to seeing your replacement. > I will just pass function pointers for now, if things should be done dirty, let's be explicit about it. Now, the hinted device attachment did work quite smoothly, however, I would have a few suggestion: 1) add a call to bus_enumerate_hinted_children() before the call DEVICE_IDENTIFY() call in bus_generic_driver_added() this is required to be able to support dynamic loading and attachment of hinted children. 2) have a generic bus_hinted_child method which would just add a new child to the bus. 3) have bus_enumerate_hinted_children() and bus_generic_attach() always ran on device attachment. There is current +100 explicit call to bus_generic_attach() in the sys/dev/ tree. This should be done always and implicitly. 4) have bus_generic_detach() always ran prior to device detachment If not already the case. There is still the same +100 direct call to bus_generic_detach is the tree. 5) have the bus_generic_* method be the default of their respective method 6) have device_delete_child() called upon device detachment. As a rule of thumb, when a kld is unloaded there should not be any remains of anything built previously. Without device_delete_child() or proper singleton implementation, multiple load/unload sequence of bus will attempt to attach multiple version of a child, even if the single child was added prior to the bus_generic_attach() call. Also, as a rule of thumb, if the same logic is implemented in more than a few buses, it should be made generic and implicit. I am lazy, I hate doing the same things over and over, not to say it raised the likelihood of bugs' introduction... - Arnaud
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