[PATCH AUTOSEL 5.6 14/68] driver core: Reevaluate dev->links.need_for_probe as suppliers are added

Sasha Levin
2020-04-10T04:02:39Z

From: Saravana Kannan <saravanak@google.com>

[ Upstream commit 1745d299af5b373abad08fa29bff0d31dc6aff21 ]

A previous patch 03324507e66c ("driver core: Allow
fwnode_operations.add_links to differentiate errors") forgot to update
all call sites to fwnode_operations.add_links. This patch fixes that.

Legend:
-> Denotes RHS is an optional/potential supplier for LHS
=> Denotes RHS is a mandatory supplier for LHS

Example:

Device A => Device X
Device A -> Device Y

Before this patch:
1. Device A is added.
2. Device A is marked as waiting for mandatory suppliers
3. Device X is added
4. Device A is left marked as waiting for mandatory suppliers

Step 4 is wrong since all mandatory suppliers of Device A have been
added.

After this patch:
1. Device A is added.
2. Device A is marked as waiting for mandatory suppliers
3. Device X is added
4. Device A is no longer considered as waiting for mandatory suppliers

This is the correct behavior.

Fixes: 03324507e66c ("driver core: Allow fwnode_operations.add_links to differentiate errors")
Signed-off-by: Saravana Kannan <saravanak@google.com>
Link: https://lore.kernel.org/r/20200222014038.180923-2-saravanak@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/base/core.c | 8 ++++++--
1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/drivers/base/core.c b/drivers/base/core.c
index dbb0f9130f42d..d32a3aefff32f 100644
--- a/drivers/base/core.c
+++ b/drivers/base/core.c
@@ -523,9 +523,13 @@ static void device_link_add_missing_supplier_links(void)

mutex_lock(&wfs_lock);
list_for_each_entry_safe(dev, tmp, &wait_for_suppliers,
- links.needs_suppliers)
- if (!fwnode_call_int_op(dev->fwnode, add_links, dev))
+ links.needs_suppliers) {
+ int ret = fwnode_call_int_op(dev->fwnode, add_links, dev);
+ if (!ret)
list_del_init(&dev->links.needs_suppliers);
+ else if (ret != -ENODEV)
+ dev->links.need_for_probe = false;
+ }
mutex_unlock(&wfs_lock);
}

--
2.20.1