Hi Guenter, On Nov 8, 2013, at 1:00 AM, Guenter Roeck wrote: > On Thu, Nov 07, 2013 at 09:46:26PM +0100, Sebastian Andrzej Siewior wrote: >> On 07.11.13, Pantelis Antoniou wrote: >>> Hi Sebastian, >> Hi Pantelis, >> >>> FWIW DT has been ported to x86. And is present on arm/powerpc/mips/arc and possibly >>> others. >> >> Yes, I know. I am the one that did the work for CE4100, the first one >> that boots with DT on x86. >> >>> So what are we talking about again? If you care about the non-DT case, why >>> don't you make a patch about how you could support Guenter's use case on >>> the x86. >> >> I am only saying that this "hot-plug a device at a non hot-plugagle bus at >> runtime" is not limited to DT but this solution is. X86 + ACPI is not >> the only limitation. ARM is (forced) going to ACPI as well as far I >> know. And this solution is limited to DT. This is what I am pointing >> out. >> > I can't tell about ARM, but I am not entirely sure how ACPI support on ARM > is going to help us on powerpc. > >>> His use case is not uncommon, believe it or not, and x86 would benefit from >>> something this flexible. >> >> I *think* a more flexible solution would be something like bus_type which is >> exposed via configfs. It would be attached behind a certain device/bus where >> the "physical" hotplug interface is. The user would then be able to read the >> configuration based on whatever information he has and could then create >> devices he likes at runtime. This wouldn't depend much on the firmware that is >> used but would require a little more work I think. >> > Quite frankly, I am interested at a solution that works and solves our problems. > I am not looking for something that is 100% perfect and may never be delivered. > +1 > Fortunately, the Linux kernel was willing to adopt multiple different file > systems, and still accepts new ones on a regular basis. If a new file system > is better, it will start getting used, and old file systems are being phased out > as fewer people use them. I would hope the same should be possible with DT > overlays and possible other future solutions for the same problem, and that > we won't have to wait for the perfect solution from day 1. > Fully agreed here. I was told open source is about scratching an itch, this is worthy of scratching. > Guenter Regards -- Pantelis -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
