From mboxrd@z Thu Jan 1 00:00:00 1970 From: Will Deacon Subject: [PATCH] dt-bindings: arm,gic-v3: require that reserved cells are always 0 Date: Wed, 3 Feb 2016 18:00:58 +0000 Message-ID: <1454522458-29643-1-git-send-email-will.deacon@arm.com> Return-path: Sender: devicetree-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org Cc: linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org, Will Deacon , Mark Rutland , Marc Zyngier List-Id: devicetree@vger.kernel.org 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 Cc: Marc Zyngier Signed-off-by: Will Deacon --- .../devicetree/bindings/interrupt-controller/arm,gic-v3.txt | 5 ++--- 1 file 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: -- 2.1.4 -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html