27.10.2020 22:30, Krzysztof Kozlowski пишет: > On Tue, Oct 27, 2020 at 10:17:19PM +0300, Dmitry Osipenko wrote: >> 27.10.2020 11:54, Krzysztof Kozlowski пишет: >>> On Mon, Oct 26, 2020 at 01:16:47AM +0300, Dmitry Osipenko wrote: >>>> Tegra20 External Memory Controller talks to DRAM chips and it needs to be >>>> reprogrammed when memory frequency changes. Tegra Memory Controller sits >>>> behind EMC and these controllers are tightly coupled. This patch adds the >>>> new phandle property which allows to properly express connection of EMC >>>> and MC hardware in a device-tree, it also put the Tegra20 EMC binding on >>>> par with Tegra30+ EMC bindings, which is handy to have. >>>> >>>> Signed-off-by: Dmitry Osipenko <digetx@xxxxxxxxx> >>>> --- >>>> .../bindings/memory-controllers/nvidia,tegra20-emc.txt | 2 ++ >>>> 1 file changed, 2 insertions(+) >>>> >>>> diff --git a/Documentation/devicetree/bindings/memory-controllers/nvidia,tegra20-emc.txt b/Documentation/devicetree/bindings/memory-controllers/nvidia,tegra20-emc.txt >>>> index 567cffd37f3f..1b0d4417aad8 100644 >>>> --- a/Documentation/devicetree/bindings/memory-controllers/nvidia,tegra20-emc.txt >>>> +++ b/Documentation/devicetree/bindings/memory-controllers/nvidia,tegra20-emc.txt >>>> @@ -12,6 +12,7 @@ Properties: >>>> irrespective of ram-code configuration. >>>> - interrupts : Should contain EMC General interrupt. >>>> - clocks : Should contain EMC clock. >>>> +- nvidia,memory-controller : Phandle of the Memory Controller node. >>> >>> It looks like you adding a required property which is an ABI break. >> The T20 EMC driver is unused so far in upstream and it will become used >> only once this series is applied. Hence it's fine to change the ABI. > > The ABI is not about upstream, but downstream. There are no other > upstreams using this ABI. Unless you have in mind that existing T20 EMC > driver was a noop, doing absolutely nothing, therefore there is no > breakage of any other users? The T20 EMC driver was a 100% noop for now. It's safe to change the ABI. The T30/124 EMC drivers have users, but these are unsafe drivers (with the known issues) until this series is applied. _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/dri-devel
