From mboxrd@z Thu Jan 1 00:00:00 1970 From: Suzuki K Poulose Subject: Re: [PATCH v2 02/10] coresight: platform: Refactor graph endpoint parsing Date: Wed, 25 Jul 2018 10:01:53 +0100 Message-ID: References: <1531997715-6767-1-git-send-email-suzuki.poulose@arm.com> <1531997715-6767-3-git-send-email-suzuki.poulose@arm.com> <20180724213031.GA22451@xps15> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: Content-Language: en-US Sender: linux-kernel-owner@vger.kernel.org To: Mathieu Poirier Cc: linux-arm-kernel , Linux Kernel Mailing List , Rob Herring , Sudeep Holla , Frank Rowand , devicetree@vger.kernel.org, Mark Rutland , Matt Sealey , Charles Garcia-Tobin , coresight@lists.linaro.org, John Horley , Mike Leach List-Id: devicetree@vger.kernel.org On 07/24/2018 10:34 PM, Mathieu Poirier wrote: > On Tue, 24 Jul 2018 at 15:30, Mathieu Poirier > wrote: >> >> 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. Me neither.. > > 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 >>> @@ -132,64 +184,33 @@ of_get_coresight_platform_data(struct device *dev, >>> + 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. Suzuki