diff options
| author | Will Deacon <will.deacon@arm.com> | 2016-02-03 18:00:58 +0000 |
|---|---|---|
| committer | Rob Herring <robh@kernel.org> | 2016-02-12 16:15:25 -0600 |
| commit | 4aff7b854611d91c5fefb1553eb4c328123095ae (patch) | |
| tree | 4f430598a995fbf80faff25d0813fdc0bc8cb9bd /Documentation | |
| parent | 5d589d81acf974d23af98044aac56c6339d659f8 (diff) | |
| download | linux-4aff7b854611d91c5fefb1553eb4c328123095ae.tar.bz2 | |
dt-bindings: arm, gic-v3: require that reserved cells are always 0
The arm,gic-v3 binding was written with good intentions and doesn't
enforce interrupt-cells to be 3, therefore making it easy to extend
the irq description in future if necessary:
> Cells 4 and beyond are reserved for future use.
Unfortunately, this sentence is immediately followed up with:
> When the 1st cell has a value of 0 or 1, cells 4 and beyond act as
> padding, and may be ignored. It is recommended that padding cells
> have a value of 0.
Consequently, any extensions to the PPI or SPI interrupt specifiers must
be able to work with random crap from legacy DTs, effectively
necessitating a new interrupt type in the first cell. Sigh.
This patch fixes the text so that additional, reserved cells are
required to be zero. This looks like a reasonable thing to require and
is already satisifed by the .dts files in-tree.
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Rob Herring <robh@kernel.org>
Diffstat (limited to 'Documentation')
| -rw-r--r-- | Documentation/devicetree/bindings/interrupt-controller/arm,gic-v3.txt | 5 |
1 files changed, 2 insertions, 3 deletions
diff --git a/Documentation/devicetree/bindings/interrupt-controller/arm,gic-v3.txt b/Documentation/devicetree/bindings/interrupt-controller/arm,gic-v3.txt index 7803e77d85cb..007a5b46256a 100644 --- a/Documentation/devicetree/bindings/interrupt-controller/arm,gic-v3.txt +++ b/Documentation/devicetree/bindings/interrupt-controller/arm,gic-v3.txt @@ -24,9 +24,8 @@ Main node required properties: 1 = edge triggered 4 = level triggered - Cells 4 and beyond are reserved for future use. When the 1st cell - has a value of 0 or 1, cells 4 and beyond act as padding, and may be - ignored. It is recommended that padding cells have a value of 0. + Cells 4 and beyond are reserved for future use and must have a value + of 0 if present. - reg : Specifies base physical address(s) and size of the GIC registers, in the following order: |