From: Xiaomeng Tong <xiam0nd.tong@gmail.com>
To: vireshk@kernel.org, nm@ti.com, sboyd@kernel.org
Cc: linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org,
Xiaomeng Tong <xiam0nd.tong@gmail.com>
Subject: [PATCH v2] opp: use list iterator only inside the loop
Date: Thu, 31 Mar 2022 16:30:18 +0800 [thread overview]
Message-ID: <20220331083018.31995-1-xiam0nd.tong@gmail.com> (raw)
To move the list iterator variable into the list_for_each_entry_*()
macro in the future it should be avoided to use the list iterator
variable after the loop body.
To *never* use the list iterator variable after the loop it was
concluded to use a separate dedicated pointer variable [1].
In this case, use a new variable 'iter' as the list iterator, while
use the old variable 'new_dev' as a dedicated pointer to point to the
found entry. And BUG_ON(!new_dev);.
[1]: https://lore.kernel.org/all/CAHk-=wgRr_D8CB-D9Kg-c=EHreAsk5SqXPwr9Y7k9sA6cWXJ6w@mail.gmail.com/
Signed-off-by: Xiaomeng Tong <xiam0nd.tong@gmail.com>
---
changes since v1:
- use BUG_ON(!new_dev); instead of return; (Viresh Kumar)
v1: https://lore.kernel.org/lkml/20220331015818.28045-1-xiam0nd.tong@gmail.com/
---
drivers/opp/debugfs.c | 10 +++++++---
1 file changed, 7 insertions(+), 3 deletions(-)
diff --git a/drivers/opp/debugfs.c b/drivers/opp/debugfs.c
index 596c185b5dda..81b2bc4b5f43 100644
--- a/drivers/opp/debugfs.c
+++ b/drivers/opp/debugfs.c
@@ -187,14 +187,18 @@ void opp_debug_register(struct opp_device *opp_dev, struct opp_table *opp_table)
static void opp_migrate_dentry(struct opp_device *opp_dev,
struct opp_table *opp_table)
{
- struct opp_device *new_dev;
+ struct opp_device *new_dev = NULL, *iter;
const struct device *dev;
struct dentry *dentry;
/* Look for next opp-dev */
- list_for_each_entry(new_dev, &opp_table->dev_list, node)
- if (new_dev != opp_dev)
+ list_for_each_entry(iter, &opp_table->dev_list, node)
+ if (iter != opp_dev) {
+ new_dev = iter;
break;
+ }
+
+ BUG_ON(!new_dev);
/* new_dev is guaranteed to be valid here */
dev = new_dev->dev;
--
2.17.1
next reply other threads:[~2022-03-31 8:30 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-03-31 8:30 Xiaomeng Tong [this message]
2022-03-31 8:44 ` [PATCH v2] opp: use list iterator only inside the loop Viresh Kumar
2022-03-31 8:51 ` Xiaomeng Tong
2022-04-11 3:02 ` Viresh Kumar
-- strict thread matches above, loose matches on Subject: below --
2022-03-31 2:36 Xiaomeng Tong
2022-03-31 2:49 ` Viresh Kumar
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