On Tue, Mar 29, 2016 at 4:39 AM, Andy Lutomirski <luto@xxxxxxxxxxxxxx> wrote: > AFAICT something got rather screwed up in i915 land for 4.5. > > $ git log --oneline --grep='Pretend cursor is always on' v4.5 > drivers/gpu/drm/i915/ > e2e407dc093f drm/i915: Pretend cursor is always on for ILK-style WM > calculations (v2) > > $ git log --oneline --grep='Pretend cursor is always on' v4.6-rc1 > drivers/gpu/drm/i915/ > e2e407dc093f drm/i915: Pretend cursor is always on for ILK-style WM > calculations (v2) > b2435692dbb7 drm/i915: Pretend cursor is always on for ILK-style WM > calculations (v2) > > The two patches there are almost, but not quite, the same thing, which > makes me wonder how they both ended up in Linus' tree without an > obvious merge conflict. > > I have no idea what caused this. However, I think (on very little > inspection, but it's consistent with problems I have with 4.5 on my > laptop) that the first one is an *incorrect* fix for a regression in > 4.5 and the second is a correct fix for the same regression. 4.6-rc1 > seems okay. > > I reported the regression and everyone involved has known about it for > weeks. Nonetheless, 4.5 final is busted. Quoting from e2e407dc093f "(cherry picked from commit b2435692dbb709d4c8ff3b2f2815c9b8423b72bb)" i.e. this is intentionally twice in the history. We started to soak bugfixes in -next and then cherry pick them because we had too much fun with things blowing up, and also too much fun with really messy conflicts. It's not a botched patch in 4.5 or anything else nefarious at all. Which just means that there's another bugfix in 4.6-rc1 that needs to be backported to 4.5 but hasn't arrived in there yet. Two possible cases: - Greg is too slow with cc: stable patches - especially around releases we occasionally put the patch into the wrong branch at first, or it simply misses the last pull. 4.6 closes for drm drivers already at 4.5-rc5, so there's a sizeable overlap where placing patches correctly requires some juggling. - We've genuinely failed to cherry-pick a bugfix over. It happens, despite our best efforts (which of course includes running stuff on Linus' tree). Please do a reverse bisect so we know which precise commit fell through the cracks. Thanks, Daniel -- Daniel Vetter Software Engineer, Intel Corporation +41 (0) 79 365 57 48 - http://blog.ffwll.ch _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/dri-devel
