Re: [PATCH 01/12] coresight replicator: Cleanup programmable replicator naming
From: Rob Herring
Date: Wed Jun 21 2017 - 23:22:13 EST
On Tue, Jun 20, 2017 at 11:44 AM, Mathieu Poirier
> On 18 June 2017 at 08:04, Rob Herring <robh@xxxxxxxxxx> wrote:
>> On Tue, Jun 13, 2017 at 10:55:28AM -0600, Mathieu Poirier wrote:
>>> On Mon, Jun 12, 2017 at 03:36:40PM +0100, Suzuki K Poulose wrote:
>>> > The Linux coresight drivers define the programmable ATB replicator as
>>> > Qualcom replicator, while this is designed by ARM. This can cause confusion
>>> > to a user selecting the driver. Cleanup all references to make it
>>> > explicitly clear. This patch :
>>> > 1) Adds a new compatible string for the same, retaining the old one for
>>> > compatibility.
>>> > 2) Changes the Kconfig symbol (since this is not part of any defconfigs)
>>> > CORESIGHT_QCOM_REPLICATOR => CORESIGHT_DYNAMIC_REPLICATOR
>>> > 3) Improves the help message in the Kconfig.
>>> > 4) Changes the name of the driver :
>>> > coresight-replicator-qcom => coresight-dynamic-replicator
>>> > Cc: Pratik Patel <pratikp@xxxxxxxxxxxxxx>
>>> > Cc: Ivan T. Ivanov <ivan.ivanov@xxxxxxxxxx>
>>> > Cc: Mathieu Poirier <mathieu.poirier@xxxxxxxxxx>
>>> > Cc: devicetree@xxxxxxxxxxxxxxx
>>> > Cc: Rob Herring <robh+dt@xxxxxxxxxx>
>>> > Cc: Mark Rutland <mark.rutland@xxxxxxx>
>>> > Signed-off-by: Suzuki K Poulose <suzuki.poulose@xxxxxxx>
>>> Hi Suzuki,
>>> > ---
>>> > Documentation/devicetree/bindings/arm/coresight.txt | 4 +++-
>>> > drivers/hwtracing/coresight/Kconfig | 10 +++++-----
>>> > drivers/hwtracing/coresight/Makefile | 2 +-
>>> > drivers/hwtracing/coresight/coresight-replicator-qcom.c | 2 +-
>>> > 4 files changed, 10 insertions(+), 8 deletions(-)
>>> > diff --git a/Documentation/devicetree/bindings/arm/coresight.txt b/Documentation/devicetree/bindings/arm/coresight.txt
>>> > index fcbae6a..f77329f 100644
>>> > --- a/Documentation/devicetree/bindings/arm/coresight.txt
>>> > +++ b/Documentation/devicetree/bindings/arm/coresight.txt
>>> > @@ -34,7 +34,9 @@ its hardware characteristcs.
>>> > - Embedded Trace Macrocell (version 4.x):
>>> > "arm,coresight-etm4x", "arm,primecell";
>>> > - - Qualcomm Configurable Replicator (version 1.x):
>>> > + - Coresight programmable Replicator (version 1.x):
>>> > + "arm,coresight-dynamic-replicator", "arm,primecell";
>>> > + OR
>>> > "qcom,coresight-replicator1x", "arm,primecell";
>>> Rob, what's your view on keeping the old binding around? We could simply change
>>> the two occurences we find in the DTs (Juno and 410c) to the new name and be
>>> done with the old one.
>> Juno uses the Qcom string? We should keep the old string. You can switch
>> the dts files, but the driver should support the old name.
> When we first started working on CoreSight programmable replicators
> were available but the documentation wasn't public. As such when I
> saw Qualcomm's design I mistakenly thought it was a custom IP block
> and came up with a compatible string that reflected that reality.
> Fast forward 3 years the documentation is available and Juno has used
> the same IP block in their design. Suzuki's patch rectifies history
> by changing the programmable replicator naming convention to what it
> should have been from the start.
> That being said, we can keep the old compatible string around but it
> won't change anything. CoreSight devices are discovered on the AMBA
> bus and don't use the compatible string - drivers are probed based on
> AMBA IDs laid out in the drivers and device IDs found in HW ID
> In light of the above let me know what you want to do.
Well, if drivers don't use the string, then there is nothing to keep around.