Re: [PATCH -next] memory: Convert to DEFINE_SHOW_ATTRIBUTE

[miaoqinglang]

å 2020/7/18 5:14, Pavel Machek åé:
> On Thu 2020-07-16 17:03:03, Qinglang Miao wrote:
> > From: Yongqiang Liu <liuyongqiang13@xxxxxxxxxx>
> >
> > Use DEFINE_SHOW_ATTRIBUTE macro to simplify the code.
> >
> > Signed-off-by: Yongqiang Liu <liuyongqiang13@xxxxxxxxxx>
> > ---
> >   drivers/memory/emif.c               | 22 ++--------------------
> >   drivers/memory/tegra/tegra124-emc.c | 14 +-------------
> >   2 files changed, 3 insertions(+), 33 deletions(-)
> >
> > diff --git a/drivers/memory/emif.c b/drivers/memory/emif.c
> > index 58a82eea5..aab8ddad7 100644
> > --- a/drivers/memory/emif.c
> > +++ b/drivers/memory/emif.c
> > @@ -131,16 +131,7 @@ static int emif_regdump_show(struct seq_file *s, void *unused)
> >   	return 0;
> >   }
> >   
> > -static int emif_regdump_open(struct inode *inode, struct file *file)
> > -{
> > -	return single_open(file, emif_regdump_show, inode->i_private);
> > -}
> > -
> > -static const struct file_operations emif_regdump_fops = {
> > -	.open			= emif_regdump_open,
> > -	.read_iter			= seq_read_iter,
> > -	.release		= single_release,
> > -};
> > +DEFINE_SHOW_ATTRIBUTE(emif_regdump);
>
> This is not equivalent (and I guess changelog should mention that).
>
> Along with other changes, we get:
>
>          .owner          = THIS_MODULE,
>          .llseek         = seq_lseek,
>
> . Is that okay thing to add?
> 									Pavel
Hi Pavel,

âYou're right, I should of mention it in changelog.

âThere's no impact theoretically with these two changes. Here's my thoughs:

1. The llseek method is used to change the current read/write position 
in a file which can be ignored if you don't use it.
2. The owner is not even a method. Instead, it is a pointer to the 
module that âownsâ this structure; it is used by the kernel to maintain 
the module's usage count which I believe can be ignored.

If you don't mind I can send a new patch with more specific changelog.

âThanks.

Qinglang

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