21.12.2021 21:01, Thierry Reding пишет: > On Tue, Dec 21, 2021 at 07:45:31PM +0300, Dmitry Osipenko wrote: >> 21.12.2021 19:17, Thierry Reding пишет: >>> On Tue, Dec 21, 2021 at 06:47:31PM +0300, Dmitry Osipenko wrote: >>>> 21.12.2021 13:58, Thierry Reding пишет: >>>> .. >>>>>>>> The panel->ddc isn't used by the new panel-edp driver unless panel is >>>>>>>> compatible with "edp-panel". Hence the generic_edp_panel_probe() should >>>>>>>> either fail or crash for a such "edp-panel" since panel->ddc isn't fully >>>>>>>> instantiated, AFAICS. >>>>>>> >>>>>>> I've tested this and it works fine on Venice 2. Since that was the >>>>>>> reference design for Nyan, I suspect that Nyan's will also work. >>>>>>> >>>>>>> It'd be great if Thomas or anyone else with access to a Nyan could >>>>>>> test this to verify that. >>>>>> >>>>>> There is no panel-edp driver in the v5.15. The EOL of v5.15 is Oct, >>>>>> 2023, hence we need to either use: >>>>> >>>>> All the (at least relevant) functionality that is in panel-edp was in >>>>> panel-simple before it was moved to panel-edp. I've backported this set >>>>> of patches to v5.15 and it works just fine there. >>>> >>>> Will we be able to add patch to bypass the panel's DT ddc-i2c-bus on >>>> Nyan to keep the older DTBs working? >>> >>> I don't see why we would want to do that. It's quite clear that the DTB >>> is buggy in this case and we have a more accurate way to describe what's >>> really there in hardware. In addition that more accurate representation >>> also gets rid of a bug. Obviously because the bug is caused by the >>> previous representation that was not accurate. >>> >>> Given that we can easily replace the DTBs on these devices there's no >>> reason to make this any more complicated than it has to be. >> >> Don't you care about normal people at all? Do you assume that everyone >> must to be a kernel developer to be able to use Tegra devices? :/ > > If you know how to install a custom kernel you also know how to replace > the DTB on these devices. > > For everyone else, once these patches are merged upstream and > distributions start shipping the new version, they will get this > automatically by updating their kernel package since most distributions > actually ship the DTB files as part of that. > >> It's not a problem for you to figure out why display is broken, for >> other people it's a problem. Usually nobody will update DTB without a >> well known reason, instead device will be dusted on a shelf. In the end >> you won't have any users at all. > > Most "normal" people aren't even going to notice that their DTB is going > to be updated. They would actually have to do extra work *not* to update > it. My past experience tells that your assumption is incorrect. There are quite a lot of people who will update kernel, but not DTB. ARM devices have endless variations of bootloaders and individual quirks required for a successful installation of a kernel. Kernel update by distro usually isn't a thing on ARM.
