On Mon, 2019-06-03 at 18:19 +0300, Andriy Gapon wrote: > On 03/06/2019 17:52, Ian Lepore wrote: > > Please don't. We still have a situation where nobody has shown a > > runtime failure at all. This build failure could be fixed by > > simply > > defining a do-nothing iicbus_set_nostop() function if a quick fix > > is > > needed. > > Well, I am quite certain that the run-time failure will follow after > the build > time failure is fixed. > > > Putting this nostop concept into code that is shared by many > > drivers is > > an abomination. We have exactly one driver that needs this > > functionality, so the right fix is to implement it wholly within > > that > > one driver. I'll put together a diff for that. > > That's true that we have just one such driver. > At the same time, the "no stop" (or rather, repeated start) behavior > makes more > sense. If stop+start between transfers are needed then that can be > done with > multiple calls to iicbus_transfer. If multiple messages are given to > iicbus_transfer, then it's reasonable to assume that a repeated > started is > wanted between them. But it would be a big change to review and, if > needed, fix > or tidy up all code that uses iicbus_transfer. So, > iicbus_set_nostop() could be > just a small step towards the bigger goal. > > But I really don't have a strong opinion. > Fixing drm2 directly is just as good for me as iicbus_set_nostop. >
I agree with you that the freebsd iic stuff is a Big Mess, poorly designed. But it is what it is, we can't change things now without breaking every out-of-tree driver in the world (and I know for sure they exist, because we have some at $work). So we're stuck with explicitly setting NOSTOP flags in iic_msg descriptors even though it would be sensible to assume NOSTOP on all but the last one. Anyway, the bad news is I mis-remembered how the iicbb interface and driver are structured. The hook point I wanted isn't there, making it hard to put the fix I was picturing in the intel_iic code. I'd still like to think of a better fix, but it's going to take more than a few minutes. So I guess we'd better go with your fix to get things working right away. If I can think up something more elegant we can always switch to it later. -- Ian _______________________________________________ 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"
