On Thu, Nov 17, 2016 at 08:17:00AM -0800, Guenter Roeck wrote: > On 11/17/2016 07:05 AM, Mark Rutland wrote: > >On Thu, Nov 17, 2016 at 06:44:55AM -0800, Guenter Roeck wrote: > >>On 11/17/2016 02:55 AM, Mark Rutland wrote: > >>>Memory nodes require this property per ePAPR and the devicetree.org > >>>spec, so the bug is that we didn't add those when removing the > >>>skeleton.dtsi include. > >> > >>The downside from qemu perspective is that the real hardware seems > >>to add the property unconditionally, or the boot failure would have > >>been seen there as well. > >> > >>I submitted https://patchwork.ozlabs.org/patch/695951/; we'll see how it > >>goes. > > > >Sure, the firmare/bootlaoder you're using may add this automatically. > > > >My worry is that adding this to a generic file in QEMU only serves to > >mask this class of bug for other boards (i.e. they'll work fine in QEMU, > >but not on real HW using whatever bootlaoder happens ot be there). > > > Good point. > > What would be the correct behavior for qemu ? Adding a chosen node if it does > not exist is one detail we already established. Also, I think a check if > /memory/device_type exists (and to bail out if it doesn't) would make sense.
We'd also need to check for /memory@<n> nodes, as they can validly have unit-addresses (and many do). Generally, the "correct" way to find them is to iterate over all ndoes with device_type = "memory", so one could do that and give up if none are found, ignoring the naming entirely. > What about the memory node ? Does it have to exist, or should it be added > (including the device_type property) if not ? I'm not sure what QEMU does in this area. I suspect it may expect a node in some cases, or may generate one in others. There's no point generating one when we don't have the information to hand, certainly. Thanks, Mark.
