On Wed, Mar 20, 2019 at 06:49:38PM +0000, Suzuki K Poulose wrote: > We rely on the device names to find a CoreSight device on the > coresight bus. The device name however is obtained from the platform, > which is bound to the real platform/amba device. As we are about > to use different naming scheme for the coresight devices, we can't > rely on the platform device name to find the corresponding > coresight device. Instead we use the platform agnostic > "fwnode handle" of the parent device to find the devices. > We also reuse the same fwnode as the parent for the Coresight > device we create. > > Cc: Mathieu Poirier <mathieu.poirier@xxxxxxxxxx> > Signed-off-by: Suzuki K Poulose <suzuki.poulose@xxxxxxx> > --- > drivers/hwtracing/coresight/coresight-platform.c | 10 ++++------ > drivers/hwtracing/coresight/coresight-priv.h | 2 ++ > drivers/hwtracing/coresight/coresight.c | 19 +++++++++++-------- > include/linux/coresight.h | 4 ++-- > 4 files changed, 19 insertions(+), 16 deletions(-) > > diff --git a/drivers/hwtracing/coresight/coresight-platform.c b/drivers/hwtracing/coresight/coresight-platform.c > index 877ed2b..5eee987 100644 > --- a/drivers/hwtracing/coresight/coresight-platform.c > +++ b/drivers/hwtracing/coresight/coresight-platform.c > @@ -31,7 +31,7 @@ static int coresight_alloc_conns(struct device *dev, > return 0; > } > > -static int coresight_fwnode_handle_match(struct device *dev, void *data) > +int coresight_match_fwnode_handle(struct device *dev, void *data) > { > return dev_fwnode(dev) == data; > } > @@ -46,7 +46,7 @@ coresight_find_device_by_fwnode(struct fwnode_handle *fwnode) > * platform bus. > */ > dev = bus_find_device(&platform_bus_type, NULL, > - fwnode, coresight_fwnode_handle_match); > + fwnode, coresight_match_fwnode_handle); > if (dev) > return dev; > > @@ -55,7 +55,7 @@ coresight_find_device_by_fwnode(struct fwnode_handle *fwnode) > * looking for the device that matches the endpoint node. > */ > return bus_find_device(&amba_bustype, NULL, > - fwnode, coresight_fwnode_handle_match); > + fwnode, coresight_match_fwnode_handle); > } Please change the name to coresight_match_fwnode_handle() in the previous patch so that it is set only once. > > #ifdef CONFIG_OF > @@ -214,9 +214,7 @@ static int of_coresight_parse_endpoint(struct device *dev, > } > > conn->outport = endpoint.port; > - conn->child_name = devm_kstrdup(dev, > - dev_name(rdev), > - GFP_KERNEL); > + conn->child_fwnode = fwnode_handle_get(rdev_fwnode); I think it is worth adding a comment saying the refcount on the handle is decremented in coresight_remove_match(). It is quite obvious when looking at this patch but I suspect it won't be so in 1 year from now when trying to understand this code again, especially since the increment/decrement are in different files. > conn->child_port = rendpoint.port; > /* Connection record updated */ > ret = 1; > diff --git a/drivers/hwtracing/coresight/coresight-priv.h b/drivers/hwtracing/coresight/coresight-priv.h > index e0684d0..8fb1243 100644 > --- a/drivers/hwtracing/coresight/coresight-priv.h > +++ b/drivers/hwtracing/coresight/coresight-priv.h > @@ -153,6 +153,8 @@ struct list_head *coresight_build_path(struct coresight_device *csdev, > struct coresight_device *sink); > void coresight_release_path(struct list_head *path); > > +int coresight_match_fwnode_handle(struct device *dev, void *data); > + > #ifdef CONFIG_CORESIGHT_SOURCE_ETM3X > extern int etm_readl_cp14(u32 off, unsigned int *val); > extern int etm_writel_cp14(u32 off, u32 val); > diff --git a/drivers/hwtracing/coresight/coresight.c b/drivers/hwtracing/coresight/coresight.c > index 29cef89..9cdedab 100644 > --- a/drivers/hwtracing/coresight/coresight.c > +++ b/drivers/hwtracing/coresight/coresight.c > @@ -1005,13 +1005,11 @@ static int coresight_orphan_match(struct device *dev, void *data) > /* We have found at least one orphan connection */ > if (conn->child_dev == NULL) { > /* Does it match this newly added device? */ > - if (conn->child_name && > - !strcmp(dev_name(&csdev->dev), conn->child_name)) { > + if (conn->child_fwnode == csdev->dev.fwnode) > conn->child_dev = csdev; > - } else { > + else > /* This component still has an orphan */ > still_orphan = true; > - } > } > } > > @@ -1043,9 +1041,9 @@ static void coresight_fixup_device_conns(struct coresight_device *csdev) > struct coresight_connection *conn = &csdev->conns[i]; > struct device *dev = NULL; > > - if (conn->child_name) > - dev = bus_find_device_by_name(&coresight_bustype, NULL, > - conn->child_name); > + dev = bus_find_device(&coresight_bustype, NULL, > + (void *)conn->child_fwnode, > + coresight_match_fwnode_handle); > if (dev) { > conn->child_dev = to_coresight_device(dev); > /* and put reference from 'bus_find_device()' */ > @@ -1080,9 +1078,11 @@ static int coresight_remove_match(struct device *dev, void *data) > if (conn->child_dev == NULL) > continue; > > - if (!strcmp(dev_name(&csdev->dev), conn->child_name)) { > + if (csdev->dev.fwnode == conn->child_fwnode) { > iterator->orphan = true; > conn->child_dev = NULL; > + /* Drop the reference to the handle for connection */ Same as above, please comment where this gets incremented. > + fwnode_handle_put(conn->child_fwnode); > /* No need to continue */ > break; > } > @@ -1198,6 +1198,8 @@ struct coresight_device *coresight_register(struct coresight_desc *desc) > csdev->dev.parent = desc->dev; > csdev->dev.release = coresight_device_release; > csdev->dev.bus = &coresight_bustype; > + csdev->dev.fwnode = fwnode_handle_get(dev_fwnode(desc->dev)); > + > dev_set_name(&csdev->dev, "%s", desc->pdata->name); > > ret = device_register(&csdev->dev); > @@ -1247,6 +1249,7 @@ void coresight_unregister(struct coresight_device *csdev) > etm_perf_del_symlink_sink(csdev); > /* Remove references of that device in the topology */ > coresight_remove_conns(csdev); > + fwnode_handle_put(csdev->dev.fwnode); > device_unregister(&csdev->dev); > } > EXPORT_SYMBOL_GPL(coresight_unregister); > diff --git a/include/linux/coresight.h b/include/linux/coresight.h > index a48cd9b..76c31b2 100644 > --- a/include/linux/coresight.h > +++ b/include/linux/coresight.h > @@ -128,14 +128,14 @@ struct coresight_desc { > /** > * struct coresight_connection - representation of a single connection > * @outport: a connection's output port number. > - * @chid_name: remote component's name. > + * @chid_fwnode: remote component's fwnode handle. > * @child_port: remote component's port number @output is connected to. > * @child_dev: a @coresight_device representation of the component > connected to @outport. > */ > struct coresight_connection { > int outport; > - const char *child_name; > + struct fwnode_handle *child_fwnode; Please drop this one line to group all the struct together. > int child_port; > struct coresight_device *child_dev; > }; > -- > 2.7.4 >