On 10/03/17 11:46, Nicolas Pitre wrote: > On Tue, 3 Oct 2017, Rob Herring wrote: > >> For static DT usecases, we don't need the disabled nodes and can skip >> unflattening. This saves a significant amount of RAM in memory constrained >> cases. In one example on STM32F469, the RAM usage goes from 118K to 26K. >> >> There are a few cases in the kernel that modify the status property >> dynamically. These all are changes from enabled to disabled, depend on >> OF_DYNAMIC or are not FDT based (PDT based). >> >> Cc: Nicolas Pitre <nicolas.pitre@xxxxxxxxxx> >> Cc: Frank Rowand <frowand.list@xxxxxxxxx> >> Signed-off-by: Rob Herring <robh@xxxxxxxxxx> > > Tested-by: Nicolas Pitre <nico@xxxxxxxxxx> > >> --- >> For more background, see this presentation from Nico: >> >> https://connect.linaro.org/resource/sfo17/sfo17-100/ > > Oh my ... this is horrible ... I found the presentation to be quite good and useful. The Linaro site does not have the slides, could you please send me a copy? Thanks, Frank > > /me hides in shame > >> >> drivers/of/fdt.c | 4 ++++ >> 1 file changed, 4 insertions(+) >> >> diff --git a/drivers/of/fdt.c b/drivers/of/fdt.c >> index f8c39705418b..efe91c6856a0 100644 >> --- a/drivers/of/fdt.c >> +++ b/drivers/of/fdt.c >> @@ -396,6 +396,10 @@ static int unflatten_dt_nodes(const void *blob, >> if (WARN_ON_ONCE(depth >= FDT_MAX_DEPTH)) >> continue; >> >> + if (!IS_ENABLED(CONFIG_OF_DYNAMIC) && >> + !of_fdt_device_is_available(blob, offset)) >> + continue; >> + >> if (!populate_node(blob, offset, &mem, nps[depth], >> &nps[depth+1], dryrun)) >> return mem - base; >> -- >> 2.11.0 >> >> > -- 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
