diff options
Diffstat (limited to 'drivers/of/dynamic.c')
| -rw-r--r-- | drivers/of/dynamic.c | 135 |
1 files changed, 115 insertions, 20 deletions
diff --git a/drivers/of/dynamic.c b/drivers/of/dynamic.c index 4bc96af4d8e2..747d87619faf 100644 --- a/drivers/of/dynamic.c +++ b/drivers/of/dynamic.c @@ -491,11 +491,12 @@ static void __of_changeset_entry_invert(struct of_changeset_entry *ce, } } -static void __of_changeset_entry_notify(struct of_changeset_entry *ce, bool revert) +static int __of_changeset_entry_notify(struct of_changeset_entry *ce, + bool revert) { struct of_reconfig_data rd; struct of_changeset_entry ce_inverted; - int ret; + int ret = 0; if (revert) { __of_changeset_entry_invert(ce, &ce_inverted); @@ -517,11 +518,12 @@ static void __of_changeset_entry_notify(struct of_changeset_entry *ce, bool reve default: pr_err("invalid devicetree changeset action: %i\n", (int)ce->action); - return; + ret = -EINVAL; } if (ret) pr_err("changeset notifier error @%pOF\n", ce->np); + return ret; } static int __of_changeset_entry_apply(struct of_changeset_entry *ce) @@ -655,32 +657,82 @@ void of_changeset_destroy(struct of_changeset *ocs) } EXPORT_SYMBOL_GPL(of_changeset_destroy); -int __of_changeset_apply(struct of_changeset *ocs) +/* + * Apply the changeset entries in @ocs. + * If apply fails, an attempt is made to revert the entries that were + * successfully applied. + * + * If multiple revert errors occur then only the final revert error is reported. + * + * Returns 0 on success, a negative error value in case of an error. + * If a revert error occurs, it is returned in *ret_revert. + */ +int __of_changeset_apply_entries(struct of_changeset *ocs, int *ret_revert) { struct of_changeset_entry *ce; - int ret; + int ret, ret_tmp; - /* perform the rest of the work */ pr_debug("changeset: applying...\n"); list_for_each_entry(ce, &ocs->entries, node) { ret = __of_changeset_entry_apply(ce); if (ret) { pr_err("Error applying changeset (%d)\n", ret); - list_for_each_entry_continue_reverse(ce, &ocs->entries, node) - __of_changeset_entry_revert(ce); + list_for_each_entry_continue_reverse(ce, &ocs->entries, + node) { + ret_tmp = __of_changeset_entry_revert(ce); + if (ret_tmp) + *ret_revert = ret_tmp; + } return ret; } } - pr_debug("changeset: applied, emitting notifiers.\n"); + + return 0; +} + +/* + * Returns 0 on success, a negative error value in case of an error. + * + * If multiple changset entry notification errors occur then only the + * final notification error is reported. + */ +int __of_changeset_apply_notify(struct of_changeset *ocs) +{ + struct of_changeset_entry *ce; + int ret = 0, ret_tmp; + + pr_debug("changeset: emitting notifiers.\n"); /* drop the global lock while emitting notifiers */ mutex_unlock(&of_mutex); - list_for_each_entry(ce, &ocs->entries, node) - __of_changeset_entry_notify(ce, 0); + list_for_each_entry(ce, &ocs->entries, node) { + ret_tmp = __of_changeset_entry_notify(ce, 0); + if (ret_tmp) + ret = ret_tmp; + } mutex_lock(&of_mutex); pr_debug("changeset: notifiers sent.\n"); - return 0; + return ret; +} + +/* + * Returns 0 on success, a negative error value in case of an error. + * + * If a changeset entry apply fails, an attempt is made to revert any + * previous entries in the changeset. If any of the reverts fails, + * that failure is not reported. Thus the state of the device tree + * is unknown if an apply error occurs. + */ +static int __of_changeset_apply(struct of_changeset *ocs) +{ + int ret, ret_revert = 0; + + ret = __of_changeset_apply_entries(ocs, &ret_revert); + if (!ret) + ret = __of_changeset_apply_notify(ocs); + + return ret; } /** @@ -707,31 +759,74 @@ int of_changeset_apply(struct of_changeset *ocs) } EXPORT_SYMBOL_GPL(of_changeset_apply); -int __of_changeset_revert(struct of_changeset *ocs) +/* + * Revert the changeset entries in @ocs. + * If revert fails, an attempt is made to re-apply the entries that were + * successfully removed. + * + * If multiple re-apply errors occur then only the final apply error is + * reported. + * + * Returns 0 on success, a negative error value in case of an error. + * If an apply error occurs, it is returned in *ret_apply. + */ +int __of_changeset_revert_entries(struct of_changeset *ocs, int *ret_apply) { struct of_changeset_entry *ce; - int ret; + int ret, ret_tmp; pr_debug("changeset: reverting...\n"); list_for_each_entry_reverse(ce, &ocs->entries, node) { ret = __of_changeset_entry_revert(ce); if (ret) { pr_err("Error reverting changeset (%d)\n", ret); - list_for_each_entry_continue(ce, &ocs->entries, node) - __of_changeset_entry_apply(ce); + list_for_each_entry_continue(ce, &ocs->entries, node) { + ret_tmp = __of_changeset_entry_apply(ce); + if (ret_tmp) + *ret_apply = ret_tmp; + } return ret; } } - pr_debug("changeset: reverted, emitting notifiers.\n"); + + return 0; +} + +/* + * If multiple changset entry notification errors occur then only the + * final notification error is reported. + */ +int __of_changeset_revert_notify(struct of_changeset *ocs) +{ + struct of_changeset_entry *ce; + int ret = 0, ret_tmp; + + pr_debug("changeset: emitting notifiers.\n"); /* drop the global lock while emitting notifiers */ mutex_unlock(&of_mutex); - list_for_each_entry_reverse(ce, &ocs->entries, node) - __of_changeset_entry_notify(ce, 1); + list_for_each_entry_reverse(ce, &ocs->entries, node) { + ret_tmp = __of_changeset_entry_notify(ce, 1); + if (ret_tmp) + ret = ret_tmp; + } mutex_lock(&of_mutex); pr_debug("changeset: notifiers sent.\n"); - return 0; + return ret; +} + +static int __of_changeset_revert(struct of_changeset *ocs) +{ + int ret, ret_reply; + + ret_reply = 0; + ret = __of_changeset_revert_entries(ocs, &ret_reply); + + if (!ret) + ret = __of_changeset_revert_notify(ocs); + + return ret; } /** |