On Tue, Jul 11, 2017 at 8:12 AM, Daniel Vetter <daniel@xxxxxxxx> wrote: > On Tue, Jul 11, 2017 at 5:05 PM, John Stultz <john.stultz@xxxxxxxxxx> wrote: >>>> > be even better if you could calculate whether the mode is valid, but I didn't >>>> > spend enough time to figure out if this is possible. >>>> >>>> Theoretically that might be possible, checking if the requested freq >>>> matches the calculated freq, and I've tried that but so far I've not >>>> been able to get it to work, as in some cases the freq on the current >>>> whitelist don't exactly match but do work on the large majority of >>>> monitors tested (while other freq have a similar error but don't work >>>> on most monitors). >>>> >>>> I'd like to spend some more time to try to refine and tune this, but >>>> having the current whitelist works fairly well, so I'm not sure its >>>> worth sitting on (this is basically the last functional patch >>>> outstanding for HiKey to fully work upstream - except the mali gpu of >>>> course), while I try to tinker and tune it. >>>> >>>> Thanks so much for the feedback! >>> >>> Yeah the proper approach is to compute your pll/clock settings and bail >>> out if those don't work. That's generally a magic spreadsheet supplied by >>> the hw validation engineers, and I honestly don't want to know how they >>> create it. Explicit modelist in the kernel sounds like a very bad hack. >> >> So without such a magic spreadsheet, how would you suggest I move this forward? >> Not having the whitelist hack and picking modes the device can't >> generate is a fairly major usability issue. > > I guess if the whitelist is the only thing I'd do 2 things differently: > - Whitelist the clocks, not modes, since that's what seems to matter here. > - Put it as close as possible to the code that comuptes the clock > settings (yet if you use the clock subsystem that's a bit hard, but > for an atomic driver this should be where this is done ...). > > Whitelist of modes looks super-hacky. Sure. The whitelist modes were easiest to use initially dealing with problem reports since the EDID numbers were what users could report working or not. But this feedback sounds reasonable, as I can map those to the underlying pixel clocks and generate a whitelist of those. I really appreciate the feedback here! thanks -john _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/dri-devel
