From bcccdb664f2734482afe7108acb1d47c587a61b2 Mon Sep 17 00:00:00 2001 From: Dmitry Baryshkov Date: Mon, 29 May 2023 11:32:46 +0300 Subject: [PATCH 12/12] base: add error messages to device_link_add() To ease debugging of device_link_add() error cases, add proper error messages. Signed-off-by: Dmitry Baryshkov --- kernel/drivers/base/core.c | 15 ++++++++++++--- 1 file changed, 12 insertions(+), 3 deletions(-) diff --git a/kernel/drivers/base/core.c b/kernel/drivers/base/core.c index 10e027e92692..e555d10cd258 100644 --- a/kernel/drivers/base/core.c +++ b/kernel/drivers/base/core.c @@ -700,6 +700,7 @@ struct device_link *device_link_add(struct device *consumer, if (flags & DL_FLAG_PM_RUNTIME && flags & DL_FLAG_RPM_ACTIVE) { if (pm_runtime_get_sync(supplier) < 0) { pm_runtime_put_noidle(supplier); + dev_info(supplier, "could not resume device\n"); return NULL; } } @@ -717,10 +718,16 @@ struct device_link *device_link_add(struct device *consumer, * SYNC_STATE_ONLY link, we don't check for reverse dependencies * because it only affects sync_state() callbacks. */ - if (!device_pm_initialized(supplier) - || (!(flags & DL_FLAG_SYNC_STATE_ONLY) && - device_is_dependent(consumer, supplier))) { + if (!device_pm_initialized(supplier)) { link = NULL; + dev_err(supplier, "PM not initialized, can not link it\n"); + goto out; + } + + if (!(flags & DL_FLAG_SYNC_STATE_ONLY) && + device_is_dependent(consumer, supplier)) { + link = NULL; + dev_err(consumer, "can not link to dependent device %s\n", dev_name(supplier)); goto out; } @@ -732,6 +739,7 @@ struct device_link *device_link_add(struct device *consumer, consumer->links.status != DL_DEV_NO_DRIVER && consumer->links.status != DL_DEV_PROBING) { link = NULL; + dev_err(consumer, "not creating a useless sync-state link\n"); goto out; } @@ -823,6 +831,7 @@ struct device_link *device_link_add(struct device *consumer, if (device_register(&link->link_dev)) { put_device(&link->link_dev); link = NULL; + dev_err(consumer, "failed to register link to %s\n", dev_name(consumer)); goto out; } -- 2.39.2