Messages in this thread | | | Subject | Re: [PATCH 08/20] coresight: dts: Cleanup device tree graph bindings | From | Suzuki K Poulose <> | Date | Mon, 11 Jun 2018 17:55:26 +0100 |
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On 11/06/18 17:52, Mathieu Poirier wrote: > On 11 June 2018 at 03:22, Suzuki K Poulose <Suzuki.Poulose@arm.com> wrote: >> On 08/06/18 22:22, Mathieu Poirier wrote: >>> >>> On Tue, Jun 05, 2018 at 10:43:19PM +0100, Suzuki K Poulose wrote: >>>> >>>> The coresight drivers relied on default bindings for graph >>>> in DT, while reusing the "reg" field of the "ports" to indicate >>>> the actual hardware port number for the connections. However, >>>> with the rules getting stricter w.r.t to the address mismatch >>>> with the label, it is no longer possible to use the port address >>>> field for the hardware port number. Hence, we add an explicit >>>> property to denote the hardware port number, "coresight,hwid" >>>> which must be specified for each "endpoint". >>>> >>>> Cc: Mathieu Poirier <mathieu.poirier@linaro.org> >>>> Cc: Sudeep Holla <sudeep.holla@arm.com> >>>> Cc: Rob Herring <robh@kernel.org> >>>> Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com> >>>> --- >>>> .../devicetree/bindings/arm/coresight.txt | 29 ++++++++++--- >>>> drivers/hwtracing/coresight/of_coresight.c | 49 >>>> +++++++++++++++++----- >>>> 2 files changed, 62 insertions(+), 16 deletions(-) >>>> >>>> diff --git a/Documentation/devicetree/bindings/arm/coresight.txt >>>> b/Documentation/devicetree/bindings/arm/coresight.txt >>>> index ed6b555..bf75ab3 100644 >>>> --- a/Documentation/devicetree/bindings/arm/coresight.txt >>>> +++ b/Documentation/devicetree/bindings/arm/coresight.txt >>>> @@ -108,8 +108,13 @@ following properties to uniquely identify the >>>> connection details. >>>> "slave-mode" >> >> >> >>>> }; >>> >>> >>> For the binding part: >>> Reviewed-by: Mathieu Poirier <mathieu.poirier@linaro.org>
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>>>> @@ -140,9 +166,6 @@ static int of_coresight_parse_endpoint(struct >>>> device_node *ep, >>>> rparent = of_graph_get_port_parent(rep); >>>> if (!rparent) >>>> break; >>>> - if (of_graph_parse_endpoint(rep, &rendpoint)) >>>> - break; >>>> - >>>> /* If the remote device is not available, defer probing >>>> */ >>>> rdev = of_coresight_get_endpoint_device(rparent); >>>> if (!rdev) { >>>> @@ -150,9 +173,15 @@ static int of_coresight_parse_endpoint(struct >>>> device_node *ep, >>>> break; >>>> } >>>> - conn->outport = endpoint.port; >>>> + child_port = of_coresight_endpoint_get_port_id(rdev, >>>> rep); >>>> + if (child_port < 0) { >>>> + ret = 0; >>> >>> >>> Why returning '0' on an error condition? Same for 'local_port' above. >>> >> >> If we are unable to parse a port, we can simply ignore the port and >> continue, which >> is what we have today with the existing code. I didn't change it and still >> think >> it is the best effort thing. We could spit a warning for such cases, if >> really needed. >> Also, the parsing code almost never fails at the moment. If it fails to find >> "reg" field, >> it is assumed to be '0'. Either way ignoring it seems harmless. That said I >> am open >> to suggestions. > > Looking at the original code I remember not mandating enpoints to be > valid for debugging purposes. That certainly helps when building up a > device tree file but also has the side effect of silently overlooking > specification problems. Fortunately the revamping you did on that > part of the code makes it very easy to change that, something I think > we should take advantage of (it can only lead to positive scenarios > where defective specifications get pointed out). > > That being said and because the original behaviour is just as > permissive, you can leave as is.
Thanks. So can I assume the Reviewed-by applies for the code now ?
Suzuki
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