lkml.org 
[lkml]   [2022]   [Mar]   [30]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
From
SubjectRe: [PATCH] opp: use list iterator only inside the loop
Date
On  Thu, 31 Mar 2022 07:42:35 +0530, Viresh Kumar wrote:

> Hi Xiaomeng,
>
> On 31-03-22, 09:58, Xiaomeng Tong wrote:
> > dev = new_dev->dev;
>
> Why is this added here ?

Sorry for that. I will delete it in next patch.

>
> >
> > As discussed before,
>
> Please remember that whatever you write here will go in the commit
> logs for ever and no one will ever know what you discussed and with
> whom.
>
> This area should describe the problem at hand.
>

ok, thank you for the suggestion.

> > we should avoid to use a list iterator variable
> > outside the loop which is considered harmful[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.
> >
> > [1]: https://lkml.org/lkml/2022/2/17/1032
> >
> > Signed-off-by: Xiaomeng Tong <xiam0nd.tong@gmail.com>
> > ---
> > drivers/opp/debugfs.c | 11 ++++++++---
> > 1 file changed, 8 insertions(+), 3 deletions(-)
> >
> > diff --git a/drivers/opp/debugfs.c b/drivers/opp/debugfs.c
> > index 596c185b5dda..a4476985e4ce 100644
> > --- a/drivers/opp/debugfs.c
> > +++ b/drivers/opp/debugfs.c
> > @@ -187,14 +187,19 @@ 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;
> > + }
> > +
> > + if (!new_dev)
>
> I will rather make this BUG_ON(!new_dev);
>

Ok, i will take it.

> > + return;
> >
> > /* new_dev is guaranteed to be valid here */
> > dev = new_dev->dev;

--
Xiaomeng Tong

\
 
 \ /
  Last update: 2022-03-31 04:22    [W:0.207 / U:0.032 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site