From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mathieu Poirier Subject: Re: [PATCH v2 02/10] coresight: platform: Refactor graph endpoint parsing Date: Tue, 24 Jul 2018 15:30:31 -0600 Message-ID: <20180724213031.GA22451@xps15> References: <1531997715-6767-1-git-send-email-suzuki.poulose@arm.com> <1531997715-6767-3-git-send-email-suzuki.poulose@arm.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <1531997715-6767-3-git-send-email-suzuki.poulose@arm.com> Sender: linux-kernel-owner@vger.kernel.org To: Suzuki K Poulose Cc: linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, robh@kernel.org, sudeep.holla@arm.com, frowand.list@gmail.com, devicetree@vger.kernel.org, mark.rutland@arm.com, matt.sealey@arm.com, charles.garcia-tobin@arm.com, coresight@lists.linaro.org, john.horley@arm.com, mike.leach@linaro.org List-Id: devicetree@vger.kernel.org Good afternoon, On Thu, Jul 19, 2018 at 11:55:06AM +0100, Suzuki K Poulose wrote: > Refactor the of graph endpoint parsing code, to make the error > handling easier. > > Cc: Mathieu Poirier > Signed-off-by: Suzuki K Poulose > --- > 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. > + } while (0); > + > + return ret; > +} > + > struct coresight_platform_data * > of_get_coresight_platform_data(struct device *dev, > const struct device_node *node) > { > int i = 0, ret = 0; > struct coresight_platform_data *pdata; > - struct of_endpoint endpoint, rendpoint; > - struct device *rdev; > struct device_node *ep = NULL; > - struct device_node *rparent = NULL; > - struct device_node *rport = NULL; > > pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL); > if (!pdata) > @@ -132,64 +184,33 @@ of_get_coresight_platform_data(struct device *dev, > > /* Use device name as sysfs handle */ > pdata->name = dev_name(dev); > + pdata->cpu = of_coresight_get_cpu(node); > > /* Get the number of input and output port for this component */ > of_coresight_get_ports(node, &pdata->nr_inport, &pdata->nr_outport); > > - if (pdata->nr_outport) { > - ret = of_coresight_alloc_memory(dev, pdata); > + /* If there are no output connections, we are done */ > + if (!pdata->nr_outport) > + return pdata; > + > + ret = of_coresight_alloc_memory(dev, pdata); > + if (ret) > + return ERR_PTR(ret); > + > + /* Iterate through each port to discover topology */ > + 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. */ > + if (of_find_property(ep, "slave-mode", NULL)) > + continue; > + > + ret = of_coresight_parse_endpoint(dev, ep, pdata, &i); > if (ret) > return ERR_PTR(ret); i++; > - > - /* Iterate through each port to discover topology */ > - do { > - /* Get a handle on a port */ > - ep = of_graph_get_next_endpoint(node, ep); > - if (!ep) > - break; > - > - /* > - * No need to deal with input ports, processing for as > - * processing for output ports will deal with them. > - */ > - if (of_find_property(ep, "slave-mode", NULL)) > - continue; > - > - /* Get a handle on the local endpoint */ > - ret = of_graph_parse_endpoint(ep, &endpoint); > - > - if (ret) > - continue; > - > - /* The local out port number */ > - pdata->outports[i] = endpoint.port; > - > - /* > - * Get a handle on the remote port and parent > - * attached to it. > - */ > - rparent = of_graph_get_remote_port_parent(ep); > - rport = of_graph_get_remote_port(ep); > - > - if (!rparent || !rport) > - continue; > - > - if (of_graph_parse_endpoint(rport, &rendpoint)) > - continue; > - > - rdev = of_coresight_get_endpoint_device(rparent); > - if (!rdev) > - return ERR_PTR(-EPROBE_DEFER); > - > - pdata->child_names[i] = dev_name(rdev); > - pdata->child_ports[i] = rendpoint.id; > - > - i++; > - } while (ep); > } > > - pdata->cpu = of_coresight_get_cpu(node); > - > return pdata; > } > EXPORT_SYMBOL_GPL(of_get_coresight_platform_data); > -- > 2.7.4 >