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first try "subsystem" link at a parent device, before guessing

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This commit is contained in:
Kay Sievers
2006-10-08 16:04:54 +02:00
parent 72605f8b01
commit 66ec64e9ad
1 changed files with 41 additions and 32 deletions
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udev_sysfs.c
+41 -32
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@@ -197,8 +197,20 @@ struct sysfs_device *sysfs_device_get(const char *devpath)
sysfs_device_set_values(dev, devpath_real, NULL, NULL);
/* get subsystem */
if (strncmp(dev->devpath, "/class/", 7) == 0) {
/* get subsystem name */
strlcpy(link_path, sysfs_path, sizeof(link_path));
strlcat(link_path, dev->devpath, sizeof(link_path));
strlcat(link_path, "/subsystem", sizeof(link_path));
len = readlink(link_path, link_target, sizeof(link_target));
if (len > 0) {
/* get subsystem from "subsystem" link */
link_target[len] = '\0';
dbg("subsystem link '%s' points to '%s'", link_path, link_target);
pos = strrchr(link_target, '/');
if (pos != NULL)
strlcpy(dev->subsystem, &pos[1], sizeof(dev->subsystem));
} else if (strncmp(dev->devpath, "/class/", 7) == 0) {
/* get subsystem from class dir */
strlcpy(dev->subsystem, &dev->devpath[7], sizeof(dev->subsystem));
pos = strchr(dev->subsystem, '/');
if (pos != NULL)
@@ -219,38 +231,26 @@ struct sysfs_device *sysfs_device_get(const char *devpath)
pos = strrchr(link_target, '/');
if (pos != NULL)
strlcpy(dev->subsystem, &pos[1], sizeof(dev->subsystem));
} else {
/* get subsystem from "subsystem" link */
strlcpy(link_path, sysfs_path, sizeof(link_path));
strlcat(link_path, dev->devpath, sizeof(link_path));
strlcat(link_path, "/subsystem", sizeof(link_path));
len = readlink(link_path, link_target, sizeof(link_target));
if (len > 0) {
link_target[len] = '\0';
dbg("subsystem link '%s' points to '%s'", link_path, link_target);
pos = strrchr(link_target, '/');
if (pos != NULL)
strlcpy(dev->subsystem, &pos[1], sizeof(dev->subsystem));
}
}
/* get driver name */
strlcpy(link_path, sysfs_path, sizeof(link_path));
strlcat(link_path, dev->devpath, sizeof(link_path));
strlcat(link_path, "/driver", sizeof(link_path));
len = readlink(link_path, link_target, sizeof(link_target));
if (len > 0) {
link_target[len] = '\0';
dbg("driver link '%s' points to '%s'", link_path, link_target);
pos = strrchr(link_target, '/');
if (pos != NULL)
strlcpy(dev->driver, &pos[1], sizeof(dev->driver));
}
} else if (strncmp(dev->devpath, "/bus/", 5) == 0 && strstr(dev->devpath, "/drivers/")) {
} else if (strstr(dev->devpath, "/drivers/") != NULL) {
strlcpy(dev->subsystem, "drivers", sizeof(dev->subsystem));
} else if (strncmp(dev->devpath, "/module/", 8) == 0) {
strlcpy(dev->subsystem, "module", sizeof(dev->subsystem));
}
/* get driver name */
strlcpy(link_path, sysfs_path, sizeof(link_path));
strlcat(link_path, dev->devpath, sizeof(link_path));
strlcat(link_path, "/driver", sizeof(link_path));
len = readlink(link_path, link_target, sizeof(link_target));
if (len > 0) {
link_target[len] = '\0';
dbg("driver link '%s' points to '%s'", link_path, link_target);
pos = strrchr(link_target, '/');
if (pos != NULL)
strlcpy(dev->driver, &pos[1], sizeof(dev->driver));
}
dbg("add to cache 'devpath=%s', subsystem='%s', driver='%s'", dev->devpath, dev->subsystem, dev->driver);
list_add(&dev->node, &dev_list);
@@ -270,6 +270,7 @@ struct sysfs_device *sysfs_device_get_parent(struct sysfs_device *dev)
/* requesting a parent is only valid for devices */
if ((strncmp(dev->devpath, "/devices/", 9) != 0) &&
(strncmp(dev->devpath, "/subsystem/", 11) != 0) &&
(strncmp(dev->devpath, "/class/", 7) != 0) &&
(strncmp(dev->devpath, "/block/", 7) != 0))
return NULL;
@@ -289,10 +290,13 @@ struct sysfs_device *sysfs_device_get_parent(struct sysfs_device *dev)
return NULL;
}
/* at the top level of class/block we want to follow the "device" link */
if (strcmp(parent_devpath, "/block") == 0) {
dbg("/block top level, look for device link");
goto device_link;
/* at the subsystems top level we want to follow the old-style "device" link */
if (strncmp(parent_devpath, "/subsystem", 10) == 0) {
pos = strrchr(parent_devpath, '/');
if (pos == &parent_devpath[10] || pos == parent_devpath || strcmp(pos, "/devices") == 0) {
dbg("/subsystem top level, look for device link");
goto device_link;
}
}
if (strncmp(parent_devpath, "/class", 6) == 0) {
pos = strrchr(parent_devpath, '/');
@@ -301,6 +305,11 @@ struct sysfs_device *sysfs_device_get_parent(struct sysfs_device *dev)
goto device_link;
}
}
if (strcmp(parent_devpath, "/block") == 0) {
dbg("/block top level, look for device link");
goto device_link;
}
/* get parent and remember it */
dev->parent = sysfs_device_get(parent_devpath);
return dev->parent;