On 19 April 2016 at 13:37, Patrick Kelsey <pkel...@freebsd.org> wrote: > > > On Tue, Apr 19, 2016 at 4:21 PM, Ian Lepore <i...@freebsd.org> wrote: >> >> On Tue, 2016-04-19 at 13:17 -0700, Juli Mallett wrote: >> > Patrick Kelsey offered an mmcspi driver for FreeBSD, but nobody >> > seemed >> > interested. I know of one proprietary branch of FreeBSD using it. >> > You might poke him if you want to know how he dealt with this, and if >> > you want to commit his driver. >> > >> >> Patrick is a committer, maybe he should just commit it. :) > > > What I believe originally held up that driver being committed (by others - > this was before my commit bit) was that I relied on some out-of-tree spibus > changes Luiz had made (as I recall, mainly being able to reserve the SPI bus > for multiple transactions), and getting those into the tree would have > required updating/testing other existing SPI drivers, based on feedback I > received at the time. All I had was the RB450G that I developed and tested > the driver with, so I really couldn't address that issue, and then work took > me in some other direction entirely. Some or all of these spibus changes > that I relied on might now be in the tree, I'm not sure offhand. I am sure > though that a huge stack of other things I need to get through has > chronically kept me from updating that driver to current and retesting. > > When I wrote that driver, I put a lot of effort into testing it against as > many different cards as I could obtain at the time - I believe 30 or so in > total, all the details are in the code that was posted to the list back > then. I encountered a number of strange/unexpected behaviors in that set of > cards, and all of that hard-won knowledge is in that driver, including a > much less complex fix for a shifted-response-data issue than you will see if > you look at the Linux mmcpsi driver (as I recall, the Linux driver has code > to arbitrarily bit-shift card response data, and to detect when that should > be done, but it turns out that can be avoided entirely by inserting idle > cycles in the right place when sending the command).
Well, we should add the SPI bus reservation code and churn stuff as needed. I think that'd be a great addition. Do you have a patchset somewhere? -adrian _______________________________________________ svn-src-head@freebsd.org mailing list https://lists.freebsd.org/mailman/listinfo/svn-src-head To unsubscribe, send any mail to "svn-src-head-unsubscr...@freebsd.org"
