On Mon, Sep 16, 2013 at 3:46 PM, Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx> wrote: > On Mon, 2013-09-16 at 10:17 -0600, Stephen Warren wrote: >> On 09/15/2013 08:57 PM, Benjamin Herrenschmidt wrote: >> > [resent to the right list this time around] >> > >> > Hi folks ! >> > >> > So I don't have the bandwidth to follow closely what's going on, but I >> > just today noticed the crackpot that went into 3.11 as part of commit: >> > >> > 9d8eab7af79cb4ce2de5de39f82c455b1f796963 >> > drivers: of: add initialization code for dma reserved memory >> > >> > Fist of all, do NOT add (or change) a binding as part of a patch >> > implementing code, it's gross. >> >> Personally, I would argue the opposite; it's much easier to see what's >> going on when it's all together in one patch. > > One patch series eventually, but not the same patch. > >> Ensuring ABI stability can >> only be achieved through code review, i.e. splitting into separate >> DT/code patches won't achieve that, so that argument doesn't affect this. >> >> ... >> > Additionally, it has the following issues: >> > >> > - It describes the "memory" node as /memory, which is WRONG >> > >> > It should be "/memory@unit-address, this is important because the Linux >> > kernel of_find_device_by_path() isn't smart enough to do partial >> > searches (unlike the real OFW one) and thus to ignore the unit address >> > for search purposes, and you *need* the unit address if you have >> > multiple memory nodes (which you typically do on NUMA machines). >> >> Perhaps /memory should have had a unit-address, but it never has had on >> ARM; see arch/arm/boot/dts/skeleton.dtsi which says: > > Well, this is a mistake ARM folks might have done from day one but it > should still be fixed :-) > > A node that has a "reg" property should have the corresponding unit > address. No, absolutely _NOT_ a requirement. Unit address is only required if needed to disambiguate two properties with the same name. If there are no ambiguities, then leaving off the unit address is much preferred. -Olof -- 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
