On Wed, 25 Jul 2018 at 03:01, Suzuki K Poulose [off-list ref] wrote:

On 07/24/2018 10:34 PM, Mathieu Poirier wrote:

quoted

On Tue, 24 Jul 2018 at 15:30, Mathieu Poirier
[off-list ref] wrote:

quoted

Good afternoon,

On Thu, Jul 19, 2018 at 11:55:06AM +0100, Suzuki K Poulose wrote:

quoted

Refactor the of graph endpoint parsing code, to make the error
handling easier.

Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
---
Changes since v1:
  - Splitted from the of_node refcounting fix, part1
---
  drivers/hwtracing/coresight/of_coresight.c | 129 +++++++++++++++++------------
  1 file changed, 75 insertions(+), 54 deletions(-)

diff --git a/drivers/hwtracing/coresight/of_coresight.c b/drivers/hwtracing/coresight/of_coresight.c
index 6880bee..68faaf8 100644
--- a/drivers/hwtracing/coresight/of_coresight.c
+++ b/drivers/hwtracing/coresight/of_coresight.c

@@ -114,17 +114,69 @@ int of_coresight_get_cpu(const struct device_node *node)
  }
  EXPORT_SYMBOL_GPL(of_coresight_get_cpu);

+/*
+ * of_coresight_parse_endpoint : Parse the given output endpoint @ep
+ * and fill the connection information in @pdata[*@i].
+ *
+ * Parses the local port, remote device name and the remote port. Also
+ * updates *@i to point to the next index, when an entry is added.
+ *
+ * Returns :
+ *    0      - If the parsing completed without any fatal errors.
+ *   -Errno  - Fatal error, abort the scanning.
+ */
+static int of_coresight_parse_endpoint(struct device *dev,
+                                    struct device_node *ep,
+                                    struct coresight_platform_data *pdata,
+                                    int *i)
+{
+     int ret = 0;
+     struct of_endpoint endpoint, rendpoint;
+     struct device_node *rparent = NULL;
+     struct device_node *rport = NULL;
+     struct device *rdev = NULL;
+
+     do {
+             /* Parse the local port details */
+             if (of_graph_parse_endpoint(ep, &endpoint))
+                     break;
+             /*
+              * Get a handle on the remote port and parent
+              * attached to it.
+              */
+             rparent = of_graph_get_remote_port_parent(ep);
+             if (!rparent)
+                     break;
+             rport = of_graph_get_remote_port(ep);
+             if (!rport)
+                     break;
+             if (of_graph_parse_endpoint(rport, &rendpoint))
+                     break;
+
+             /* If the remote device is not available, defer probing */
+             rdev = of_coresight_get_endpoint_device(rparent);
+             if (!rdev) {
+                     ret = -EPROBE_DEFER;
+                     break;
+             }
+
+             pdata->outports[*i] = endpoint.port;
+             pdata->child_names[*i] = dev_name(rdev);
+             pdata->child_ports[*i] = rendpoint.id;
+             /* Move the index */
+             (*i)++;

Not a big fan, makes the code needlessly complex.  Incrementation of the index
can be done in the while loop of of_get_coresight_platform_data().  See below.

Me neither..

quoted

Void that - it properly deals with the first of_parse_endpoint().

Or may be we could do something with the return value :

          1 - Successfully parsed and populated a connection entry
          0 - No errors in parsing
        < 0 - Errors in parsing

Right, that is another solution.  I usually try to avoid those but I
think it is better than what we currently have.

quoted

quoted

quoted

@@ -132,64 +184,33 @@ of_get_coresight_platform_data(struct device *dev,

quoted

quoted

quoted

+     while ((ep = of_graph_get_next_endpoint(node, ep))) {
+             /*
+              * No need to deal with input ports, processing for as
+              * processing for output ports will deal with them.
+              */

This comment has been broken for a while... It should read:

                 /*
                  * No need to deal with input ports, as processing
                  * for output ports will deal with them.
                  */

Sure, will fix it.

Thanks,
Mathieu

Suzuki
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