On Tue, Apr 19, 2016 at 4:38 PM, Adrian Chadd <adrian.ch...@gmail.com> wrote:
> 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? > > Just going from memory here - there is what I posted to the list, then at some point Luiz took a stab at updating it to then-current (I should have a copy of those somewhere - not sure where else they went, if anywhere), and beyond that, I think there's a harmless but unnecessary conditional in the original code that could be removed. -Patrick _______________________________________________ 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"
