From: swarren@wwwdotorg.org (Stephen Warren) Date: Fri, 16 Aug 2013 12:31:57 -0600 Subject: [PATCH v2] drivers: CCI: add ARM CCI PMU support In-Reply-To: <1376673599-3967-1-git-send-email-punit.agrawal@arm.com> References: <1374571176-11584-1-git-send-email-punit.agrawal@arm.com> <1376673599-3967-1-git-send-email-punit.agrawal@arm.com> Message-ID: <520E701D.6040006@wwwdotorg.org> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On 08/16/2013 11:19 AM, Punit Agrawal wrote: > The CCI PMU can profile bus transactions at the master and slave > interfaces of the CCI. The PMU can be used to observe an aggregated view > of the bus traffic between the various components connected to the CCI. > > Extend the existing CCI driver to support the PMU by registering a perf > backend for it. I think this binding addresses my comments, thanks. Just one comment below: > diff --git a/Documentation/devicetree/bindings/arm/cci.txt b/Documentation/devicetree/bindings/arm/cci.txt > + - reg: > + Usage: required > + Value type: > + - interrupts: > + Usage: required > + Value type: That makes it sound like the layout/content of those two properties is the same. That's not true; one is an array of (base, size) cells, and the other is of (phandle, args*) cells. The difference between the data being phandles-vs-integers seems important. Perhaps says: Value type: Integer cells. Array of register entries, each expressed as a pair of cells, containing base and size. Value type: Integer cells. Array of interrupt specifier entries, as defined in ../interrupt-controller/interupts.txt. > + Definition: comma-separated list of counter overflow Oh, and lists of cells aren't necessarily comma-separated; comma is used between <> but not inside <>, and there's no requirement that each individual interrupt specifier be in its own <>, vs. just aggregating all of them into a single <>.