On Fri, Nov 10, 2023 at 6:12 PM Doug Anderson <dianders@xxxxxxxxxxxx> wrote: > > Hi, > > On Thu, Nov 9, 2023 at 5:52 AM Rob Herring <robh+dt@xxxxxxxxxx> wrote: > > > > > > End of background from Doug's cover letter. > > > > > > I think that using "status" is not a good idea, I find that confusing. > > > > "status" is what defines a device's state in terms of enabled, > > present, available. That's exactly what we're expressing here. > > > > Now, I do not think we should be mixing the device class (e.g. > > touchscreen) into status. I said this on v1, but apparently that was > > not listened to. > > Interesting. I must have missed the "don't mix device class into > status" part. Do you have a link to your post about that? Maybe > there's other stuff I missed... Having the device class stuck at the > end there was at least part of my last post [1] which gathered no > response. https://lore.kernel.org/all/CAL_JsqKK0tjeXNv=a8L3k0AjhCa15XOq1tPWqVod9mycsKXJHg@xxxxxxxxxxxxxx/ "I would not combine the 2 things. Knowing the class/type of the device may be useful independent of your problem." > I think one of the reasons that I felt we needed to mux the device > class into status was that it was going to make the code a lot less > fragile. Everything I've seen indicates that you don't want us to > create a "HW prober" node that could be used to provide relevant > phandles for different classes of devices, so the "HW prober" code > needs to either search through the whole device tree for a status of > "failed-needs-probe" or needs to contain per-board, hardcoded, > fully-qualified paths. > > I don't think we want to include hardcoded, fully-qualified paths in > the code. That would mean that if someone changed a node name > somewhere in the path to one of the devices that we're dealing with > then it would break. Right, nothing should depend on the full path. That's not an ABI just like the device path in sysfs is not (despite what Android HALs do). > So if we're searching the whole device tree for "failed-needs-probe" > then we need to figure out which devices are related to each other. If > a given board has second sources for MIPI panels, touchscreens, and > trackpads then we need to know which of the "failed-needs-probe" > devices are trackpads, which are touchscreens, and which are MIPI > panels. Do you have any suggestions for how we should do that? Maybe > it was in some other thread that I missed? I guess we could have a > board-specific table mapping (compatible + node name + reg) to a > class, but that feels awkward. Node name is supposed to correspond to device class, so why not use that (no path or unit-address.) and nothing else (well, besides "status")? Rob
