Hi Sricharan, On Fri, Jan 06, 2017 at 04:24:00PM +0000, Lorenzo Pieralisi wrote: > On Thu, Jan 05, 2017 at 08:21:53PM +0530, Sricharan wrote: > > Hi, > > > > [...] > > > > >>> > > >>> With the thinking of taking this series through, would it be fine if i > > >>> cleanup the pci configure hanging outside and push it in to > > >>> of/acpi_iommu configure respectively ? This time with all neeeded for > > >>> ACPI added as well. Also on the last post of V4, Lorenzo commented > > >>> that it worked for him, although still the of_match_node equivalent in > > >>> ACPI has to be added. If i can get that, then i will add that as well > > >>> to make this complete. > > >> > > >> Question: I had a look into this and instead of fiddling about with the > > >> linker script entries in ACPI (ie IORT_ACPI_DECLARE - which I hope this > > >> patchset would help remove entirely), I think that the only check we > > >> need in IORT is, depending on what type of SMMU a given device is > > >> connected to, to check if the respective SMMU driver is compiled in the > > >> kernel and it will be probed, _eventually_. > > >> > > >> As Robin said, by the time a device is probed the respective SMMU > > >> devices are already created and registered with IORT kernel code or > > >> they will never be, so to understand if we should defer probing > > >> SMMU device creation is _not_ really a problem in ACPI. > > >> > > >> To check if a SMMU driver is enabled, do we really need a linker > > >> table ? > > >> > > >> Would not a check based on eg: > > >> > > >> /** > > >> * @type: IOMMU IORT node type of the IOMMU a device is connected to > > >> */ > > >> static bool iort_iommu_driver_enabled(u8 type) > > >> { > > >> switch (type) { > > >> case ACPI_IORT_SMMU_V3: > > >> return IS_ENABLED(CONFIG_ARM_SMMU_V3); > > > > > >IS_BUILTIN(...) > > > > > >> case ACPI_IORT_SMMU: > > >> return IS_ENABLED(CONFIG_ARM_SMMU); > > >> default: > > >> pr_warn("Unknown IORT SMMU type\n"); > > > > > >Might displaying the actual value be helfpul for debugging a broken IORT > > >table? > > > > > >> return false; > > >> } > > >> } > > >> > > >> be sufficient (it is a bit gross, agreed, but it is to understand if > > >> that's all we need) ? Is there anything I am missing ? > > >> > > >> Let me know, I will put together a patch for you I really do not > > >> want to block your series for this trivial niggle. > > > > > >Other than that, though, I like it :) IORT has a small, strictly > > >bounded, set of supported devices, so I really don't see the need to go > > >overboard putting it on parity with DT when something this neat and > > >simple will suffice. > > > > > > > Ok sure, looks correct for me as well in whole of the context here. > > Ok, I put together a branch where you can find your original series > plus some ACPI patches for you to test and use: > > git://git.kernel.org/pub/scm/linux/kernel/git/lpieralisi/linux.git iommu/probe-deferral > > Feel free to post the additional patches I added along with your series > (that from what I gather you have reworked already) and please both have a > look if the deferral mechanism I put in place in ACPI makes sense to you. Did you have time to make progress on this ? I think it is time we posted the complete series to aim for 4.11 please, if you need help just let us know. Thanks ! Lorenzo -- To unsubscribe from this list: send the line "unsubscribe linux-arm-msm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html