On Tue, 9 Apr 2024 at 21:27, Konrad Dybcio <konrad.dybcio@xxxxxxxxxx> wrote: > > > > On 4/9/24 20:15, Dmitry Baryshkov wrote: > > On Tue, Apr 09, 2024 at 08:07:56PM +0200, Konrad Dybcio wrote: > >> > >> > >> On 4/9/24 20:04, Dmitry Baryshkov wrote: > >>> On Tue, Apr 09, 2024 at 10:12:00AM -0700, Rob Clark wrote: > >>>> On Tue, Apr 9, 2024 at 8:23 AM Dmitry Baryshkov > >>>> <dmitry.baryshkov@xxxxxxxxxx> wrote: > >>>>> > >>>>> On Tue, Apr 09, 2024 at 05:12:46PM +0200, Konrad Dybcio wrote: > >>>>>> > >>>>>> > >>>>>> On 4/6/24 04:56, Dmitry Baryshkov wrote: > >>>>>>> On Fri, Apr 05, 2024 at 10:41:31AM +0200, Konrad Dybcio wrote: > >>>>>>>> From: Neil Armstrong <neil.armstrong@xxxxxxxxxx> > >>>>>>>> > >>>>>>>> Usually, speedbin 0 is the "super SKU", a.k.a the one which can clock > >>>>>>>> the highest. Falling back to it when things go wrong is largely > >>>>>>>> suboptimal, as more often than not, the top frequencies are not > >>>>>>>> supposed to work on other bins. > >>>>>>> > >>>>>>> Isn't it better to just return an error here instead of trying to guess > >>>>>>> which speedbin to use? > >>>>>> > >>>>>> Not sure. I'd rather better compatibility for e.g. booting up a new > >>>>>> laptop with just dt. > >>>>> > >>>>> New speedbin can have lower max speed, so by attempting to run it at > >>>>> higher freq you might be breaking it. > >>>> > >>>> Usually there are some OPPs in common to all speedbins, so picking a > >>>> freq from that set would seem like the safe thing to do > >>> > >>> Well, the issue is about an uknown speed bin. So in theory we know > >>> nothing about the set of speeds itsupports. My point is that we should > >>> simplfy fail in such case. > >> > >> Or we could allow e.g. the lowest frequency (or 2) which if often shared > >> across the board to work, giving a compromise between OOBE and sanity > > > > That's also an option. But we should not be using existing speed table for > > the unknown bin. > > I derived this logic from msm-5.15 where it's "intended behavior".. I > suppose we can do better as you said though > > There have been cases in the past where the default speed bin ended up > having a higher max freq than subsequent ones, and I don't think I can > trust this product/feature code approach to guarantee this never > happening again. > > So. I think sticking to a single lowest freq and printing a big red line > in dmesg makes sense here Make 0x80 the default supported-hw, make sure that the lowest freq has 0xff. Plus big-red-line. And hope that we'll never see 16 speed bins for the hardware. -- With best wishes Dmitry
