On Mon, Dec 05, 2016 at 06:11:44PM +0100, Thierry Reding wrote: > On Mon, Dec 05, 2016 at 05:21:24PM +0100, Daniel Vetter wrote: > > On Mon, Dec 05, 2016 at 12:11:46PM +0100, Thierry Reding wrote: > > > On Mon, Dec 05, 2016 at 09:16:27AM +0100, Daniel Vetter wrote: > > > > On Mon, Dec 05, 2016 at 08:57:43AM +0100, Thierry Reding wrote: > > > > > On Sat, Dec 03, 2016 at 04:35:24AM +0000, Sharma, Shashank wrote: > > > > > > Hi Thierry, > > > > > > > > > > > > If you can please have a look on this patch, I had written one to parse HF-VSDB, which was covering SCDC detection too. > > > > > > https://patchwork.kernel.org/patch/9452259/ > > > > > > > > > > I think there had been pushback before about caching capabilities from > > > > > EDID, so from that point of view my patch is more inline with existing > > > > > EDID parsing API. > > > > > > > > Hm, where was that pushback? We do have a bit a mess between explicitly > > > > parsing stuff (e.g. eld) and stuffing parsed data into drm_display_info. > > > > > > You did object to a very similar patch some time ago that did a similar > > > thing for DPCD stuff. And also Villa had commented on an earlier patch > > > from Jose about concerns of bloating core structures: > > > > > > https://patchwork.freedesktop.org/patch/104806/ > > > > DPCD I complained about because somehow we ended up with 2 sets of > > helpers, one filling a struct and the others returning directly. I > > objected to the fact that there's 2 (and imo your patch duplicated even > > more), not that I think one approach is clearly inferior to the other. > > My recollection is that I had proposed that I do the work of > transitioning users of the parsers to the cached information but you had > said that it wasn't worth the churn and that we should just go with the > existing scheme of passing around the DPCD buffer and extending the > parsers as necessary. Hm, I guess it wasn't clear to me that you've offered to do all the conversions. Doing that would be awesome I think (but quite a bit of work), and if we bother with it, parsing into a struct is imo the better idea long-term. > From that I inferred that the same would be true for EDID and since we > already have a couple of helpers that operate on struct edid * and which > return features, continuing that scheme was preferred. > > Anyway, I don't really care either way. Maybe you and Ville can duke it > out whether or not we want all of the fields parsed, irrespective of > whether or not they will be used. Then I'll go with whatever you decide. > > > Demanding that there's some real users is also a valid point. > > > > > > I think long-term stuffing it into drm_display_info is probably better, > > > > since then we only have 1 interaction point between the probe code and the > > > > atomic_check code. That should be useful for eventually fixing the lack of > > > > locking between the two, if I ever get around to that ;-) > > > > > > I don't really have objections to caching the results of parsing, it's > > > what I had proposed and what seemed most natural back when I was working > > > on the DPCD helpers. But if we now agree that this is the preferred way > > > to do things, then we should at least agree that it applies to all areas > > > for the sake of consistency. > > > > > > Also, it might be worth looking into improving the structures, and maybe > > > adding new ones to order things more conveniently or at least group them > > > in some logical way. In my opinion some of our data structures are > > > becoming somewhat... unwieldy. > > > > We're pretty good at consuming fairly invasive refactorings in drm-misc. > > So it just boils down to get some agreement on what things should look > > like (+1 from my side to parsing stuff into structs as a general idea), > > and then massaging all the existing users of the "wrong" interface using > > cocci and sed. > > > > Unfortunately "just" ;-) > > I think by now it would be useful to have a nested structure within > struct drm_display_info that contains HDMI specific bits. We already > have a number of candidates that could be extracted into such a > structure (drm_detect_hdmi_monitor(), drm_detect_monitor_audio(), > drm_rgb_quant_range_selectable(), ...). > > Another possibility would be to subclass struct drm_display_info, as > in: > > struct drm_hdmi_info { > struct drm_display_info display; > > /* HDMI specific information */ > ... > }; > > Or yet another would be to create struct drm_hdmi_info as a separate > structure and provide a helper which will extract the necessary info > from the EDID. Drivers could then store that in driver-private data > whereas struct drm_display_info could be reduced to the generic bits > that it used to have. I think nested drm_hdmi_info within drm_display_info sounds like a fine idea. -Daniel -- Daniel Vetter Software Engineer, Intel Corporation http://blog.ffwll.ch _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/dri-devel
