On Mon, 09 Sep 2019, Manasi Navare <manasi.d.navare@xxxxxxxxx> wrote: > On Thu, Sep 05, 2019 at 11:03:12AM +0530, Nautiyal, Ankit K wrote: >> Hi, >> >> I was able to get 5K HPz27q 317b monitor for some time. Below are the >> observation on HPz27q Monitor with two DP cables connected to a KBL machine. >> >> *****General Observation***** >> The monitor settings has two modes, DP1.0 and DP1.2. >> One of the connector is enumerated as 'tiled' and the other as non tiled. >> >> The non-tiled connector has modes starting from 2K and below, and the tiled >> connector has just one mode 2560x2880. >> No corruption observed in this case. >> >> In case of DP2.0 two connectors are enumerated, both tiled. >> One connector has modes from 3849x2160 and below. 2560x2880 being preferred >> mode. >> The other has 2560x2880 mode, also preferred. >> >> The issue is seen when both the modes selected are 2560x2880. This results >> like two halves of screens not in sync. >> >> *****Experiment with different patches***** >> >> As discussed I collected logs in 3 cases: >> 1. Without any patch (vanilla) >> 2. With patch to prune the 2560x2880 mode, only for tile with HLOC and VLOC >> as 0. >> 3. With a patch to force the connector property as 'false' >> >> Logs for which are attached in fdo bug #97244 >> https://bugs.freedesktop.org/show_bug.cgi?id=97244 >> https://bugs.freedesktop.org/attachment.cgi?id=145267 >> >> Note 1: I had changed the display info to provide the Tile information, in >> case the connector 'has_tile' is true. >> Note 2: I had checked and collected logs with single display and also with >> dual display configuration with DP1.2 monitor settings. >> Note 3: The mode is changed using xrandr. >> >> case1: >> -Without any patch : 2560x2880 modeset on both connectors causes corruption. >> >> case2: >> -With 2560x2880 mode pruned for one of the tile : Only one of the connector >> shows 2560x2880 mode. >> 2560x2880 modeset on any the remaining connector resulted in blank screen. >> Any other modeset works. >> >> case3: >> -With has_tile connector property forcibly reset : The connector are listed >> as not tiled but still, 2560x2880 modeset on any the connectors causes blank >> screen. >> Any other modeset works. >> >> To summarize, pruning on just one tiled connector does not solve the issue, >> if we need to prune, we need to do it for both the connectors. >> Secondly, the forcible setting of has_tile = 'false' also, does not help, >> and resulted in blank screen when 2560x2880 mode is applied. >> So IMHO if we need to prune the mode 2560x2880, we need to prune it for both >> the connectors. >> > > Thanks Ankit for these experiments and logs. > So looks like the solution would be to add a quirk for thsi specific EDID for > the panel and then prune 2560x2880 on both connectors. > > Jani does that sound like a good acceptable solution? So you'd have to disable the mode for both displays, but then it would seem odd to expose the tiling configuration with a non-existing mode, wouldn't it? The quirk should be: on these displays, disable tiling and prune the modes listed in the tile info. That's a fairly generic quirk that makes sense to *define* in drm. However you'd only *implement* that quirk in affected drivers, i.e. i915. The question remains, what does it take to actually fix this? I haven't looked at the patches in detail, what makes them so icl specific? I'll repeat what I said up-thread: On Wed, 28 Aug 2019, Jani Nikula <jani.nikula@xxxxxxxxxxxxxxx> wrote: > Finally, and perhaps most importantly, there are people on the bug that > are going to be rather underwhelmed that after three years they get a > patch that simply rejects the very mode that was the reason for buying > the display they have. Insult to injury, the real fix is for a platform > that didn't exist when they bought the displays. Some of those folks apparently can actually make it work when they try hard enough. You'd take that away too. BR, Jani. -- Jani Nikula, Intel Open Source Graphics Center _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/intel-gfx
