diff options
author | Jakub Kicinski | 2021-10-07 15:24:06 -0700 |
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committer | Jakub Kicinski | 2021-10-07 15:24:06 -0700 |
commit | 9fe1155233c8290ca6e206053e531ef87f9026ea (patch) | |
tree | ef0d45b2562e01beb8ce4cb4cd016155b4e32a65 /drivers/base | |
parent | c514fbb6231483b05c97eb22587188d4c453b28e (diff) | |
parent | 1da38549dd64c7f5dd22427f12dfa8db3d8a722b (diff) |
Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
No conflicts.
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'drivers/base')
-rw-r--r-- | drivers/base/core.c | 90 |
1 files changed, 63 insertions, 27 deletions
diff --git a/drivers/base/core.c b/drivers/base/core.c index e65dd803a453..15986cc2fe5e 100644 --- a/drivers/base/core.c +++ b/drivers/base/core.c @@ -95,6 +95,8 @@ int fwnode_link_add(struct fwnode_handle *con, struct fwnode_handle *sup) list_add(&link->s_hook, &sup->consumers); list_add(&link->c_hook, &con->suppliers); + pr_debug("%pfwP Linked as a fwnode consumer to %pfwP\n", + con, sup); out: mutex_unlock(&fwnode_link_lock); @@ -102,6 +104,21 @@ out: } /** + * __fwnode_link_del - Delete a link between two fwnode_handles. + * @link: the fwnode_link to be deleted + * + * The fwnode_link_lock needs to be held when this function is called. + */ +static void __fwnode_link_del(struct fwnode_link *link) +{ + pr_debug("%pfwP Dropping the fwnode link to %pfwP\n", + link->consumer, link->supplier); + list_del(&link->s_hook); + list_del(&link->c_hook); + kfree(link); +} + +/** * fwnode_links_purge_suppliers - Delete all supplier links of fwnode_handle. * @fwnode: fwnode whose supplier links need to be deleted * @@ -112,11 +129,8 @@ static void fwnode_links_purge_suppliers(struct fwnode_handle *fwnode) struct fwnode_link *link, *tmp; mutex_lock(&fwnode_link_lock); - list_for_each_entry_safe(link, tmp, &fwnode->suppliers, c_hook) { - list_del(&link->s_hook); - list_del(&link->c_hook); - kfree(link); - } + list_for_each_entry_safe(link, tmp, &fwnode->suppliers, c_hook) + __fwnode_link_del(link); mutex_unlock(&fwnode_link_lock); } @@ -131,11 +145,8 @@ static void fwnode_links_purge_consumers(struct fwnode_handle *fwnode) struct fwnode_link *link, *tmp; mutex_lock(&fwnode_link_lock); - list_for_each_entry_safe(link, tmp, &fwnode->consumers, s_hook) { - list_del(&link->s_hook); - list_del(&link->c_hook); - kfree(link); - } + list_for_each_entry_safe(link, tmp, &fwnode->consumers, s_hook) + __fwnode_link_del(link); mutex_unlock(&fwnode_link_lock); } @@ -975,6 +986,7 @@ int device_links_check_suppliers(struct device *dev) { struct device_link *link; int ret = 0; + struct fwnode_handle *sup_fw; /* * Device waiting for supplier to become available is not allowed to @@ -983,10 +995,11 @@ int device_links_check_suppliers(struct device *dev) mutex_lock(&fwnode_link_lock); if (dev->fwnode && !list_empty(&dev->fwnode->suppliers) && !fw_devlink_is_permissive()) { - dev_dbg(dev, "probe deferral - wait for supplier %pfwP\n", - list_first_entry(&dev->fwnode->suppliers, - struct fwnode_link, - c_hook)->supplier); + sup_fw = list_first_entry(&dev->fwnode->suppliers, + struct fwnode_link, + c_hook)->supplier; + dev_err_probe(dev, -EPROBE_DEFER, "wait for supplier %pfwP\n", + sup_fw); mutex_unlock(&fwnode_link_lock); return -EPROBE_DEFER; } @@ -1001,8 +1014,9 @@ int device_links_check_suppliers(struct device *dev) if (link->status != DL_STATE_AVAILABLE && !(link->flags & DL_FLAG_SYNC_STATE_ONLY)) { device_links_missing_supplier(dev); - dev_dbg(dev, "probe deferral - supplier %s not ready\n", - dev_name(link->supplier)); + dev_err_probe(dev, -EPROBE_DEFER, + "supplier %s not ready\n", + dev_name(link->supplier)); ret = -EPROBE_DEFER; break; } @@ -1722,6 +1736,25 @@ static int fw_devlink_create_devlink(struct device *con, struct device *sup_dev; int ret = 0; + /* + * In some cases, a device P might also be a supplier to its child node + * C. However, this would defer the probe of C until the probe of P + * completes successfully. This is perfectly fine in the device driver + * model. device_add() doesn't guarantee probe completion of the device + * by the time it returns. + * + * However, there are a few drivers that assume C will finish probing + * as soon as it's added and before P finishes probing. So, we provide + * a flag to let fw_devlink know not to delay the probe of C until the + * probe of P completes successfully. + * + * When such a flag is set, we can't create device links where P is the + * supplier of C as that would delay the probe of C. + */ + if (sup_handle->flags & FWNODE_FLAG_NEEDS_CHILD_BOUND_ON_ADD && + fwnode_is_ancestor_of(sup_handle, con->fwnode)) + return -EINVAL; + sup_dev = get_dev_from_fwnode(sup_handle); if (sup_dev) { /* @@ -1772,14 +1805,21 @@ static int fw_devlink_create_devlink(struct device *con, * be broken by applying logic. Check for these types of cycles and * break them so that devices in the cycle probe properly. * - * If the supplier's parent is dependent on the consumer, then - * the consumer-supplier dependency is a false dependency. So, - * treat it as an invalid link. + * If the supplier's parent is dependent on the consumer, then the + * consumer and supplier have a cyclic dependency. Since fw_devlink + * can't tell which of the inferred dependencies are incorrect, don't + * enforce probe ordering between any of the devices in this cyclic + * dependency. Do this by relaxing all the fw_devlink device links in + * this cycle and by treating the fwnode link between the consumer and + * the supplier as an invalid dependency. */ sup_dev = fwnode_get_next_parent_dev(sup_handle); if (sup_dev && device_is_dependent(con, sup_dev)) { - dev_dbg(con, "Not linking to %pfwP - False link\n", - sup_handle); + dev_info(con, "Fixing up cyclic dependency with %pfwP (%s)\n", + sup_handle, dev_name(sup_dev)); + device_links_write_lock(); + fw_devlink_relax_cycle(con, sup_dev); + device_links_write_unlock(); ret = -EINVAL; } else { /* @@ -1858,9 +1898,7 @@ static void __fw_devlink_link_to_consumers(struct device *dev) if (!own_link || ret == -EAGAIN) continue; - list_del(&link->s_hook); - list_del(&link->c_hook); - kfree(link); + __fwnode_link_del(link); } } @@ -1912,9 +1950,7 @@ static void __fw_devlink_link_to_suppliers(struct device *dev, if (!own_link || ret == -EAGAIN) continue; - list_del(&link->s_hook); - list_del(&link->c_hook); - kfree(link); + __fwnode_link_del(link); /* If no device link was created, nothing more to do. */ if (ret) |