RE: [PATCH v3 1/2] usb: dwc3: make dwc3_debugfs_init return value be void

[Felipe Balbi]

Hi,

"Du, Changbin"  writes:
>> >root = debugfs_create_dir(dev_name(dwc->dev), NULL);
>> > -  if (!root) {
>> > -  ret = -ENOMEM;
>> > -  goto err0;
>> > -  }
>> > +  if (IS_ERR_OR_NULL(root))
>> > +  return;
>> 
>> We can definitely keep on going, but I'd still like to know that we
>> enabled CONFIG_DEBUG_FS but failed to create a file or a
>> directory. Seems like this should read as follows:
>> 
>>  if (IS_ERR_OR_NULL(root)) {
>>  if (!root)
>>  dev_err(dwc->dev, "Can't create debugfs root\n");
>>  return;
>>  }
>> 
>> ditto to all bellow.
>> 
> Balbi, so you mean we should not let the failure go silent,  right?

yeah, but only iff CONFIG_DEBUG_FS is enabled. From what I can tell, in
case CONFIG_DEBUG_FS is enabled and it fails, it'll return a NULL
pointer instead of ERR_PTR() ;-)

>> >dwc->root = root;
>> >
>> >dwc->regset = kzalloc(sizeof(*dwc->regset), GFP_KERNEL);
>> >if (!dwc->regset) {
>> > -  ret = -ENOMEM;
>> > -  goto err1;
>> > +  debugfs_remove_recursive(root);
>> 
>> you're now duplicating debugfs_remove_recursive(root) in all braches and
>> that's error prone. It's probably better to keep our gotos, but change
>> them so they read as follows:
>> 
>>  if (!dwc->regset)
>>  goto err1;
>> 
>>  [...]
>> 
>> return; /* this is our successful exit point */
>> 
>> err1:
>>  debugfs_remove_recursive(root);
>> kfree(dwc->regset);
>> 
>> 
>> --
>> Balbi
>
> No, no need anymore. Because no branch share this code now.
> Then remove the goto would make code a little clear.

fair enough.

-- 
balbi


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RE: [PATCH v3 1/2] usb: dwc3: make dwc3_debugfs_init return value be void

[Felipe Balbi]

Hi,

"Du, Changbin"  writes:
>> >root = debugfs_create_dir(dev_name(dwc->dev), NULL);
>> > -  if (!root) {
>> > -  ret = -ENOMEM;
>> > -  goto err0;
>> > -  }
>> > +  if (IS_ERR_OR_NULL(root))
>> > +  return;
>> 
>> We can definitely keep on going, but I'd still like to know that we
>> enabled CONFIG_DEBUG_FS but failed to create a file or a
>> directory. Seems like this should read as follows:
>> 
>>  if (IS_ERR_OR_NULL(root)) {
>>  if (!root)
>>  dev_err(dwc->dev, "Can't create debugfs root\n");
>>  return;
>>  }
>> 
>> ditto to all bellow.
>> 
> Balbi, so you mean we should not let the failure go silent,  right?

yeah, but only iff CONFIG_DEBUG_FS is enabled. From what I can tell, in
case CONFIG_DEBUG_FS is enabled and it fails, it'll return a NULL
pointer instead of ERR_PTR() ;-)

>> >dwc->root = root;
>> >
>> >dwc->regset = kzalloc(sizeof(*dwc->regset), GFP_KERNEL);
>> >if (!dwc->regset) {
>> > -  ret = -ENOMEM;
>> > -  goto err1;
>> > +  debugfs_remove_recursive(root);
>> 
>> you're now duplicating debugfs_remove_recursive(root) in all braches and
>> that's error prone. It's probably better to keep our gotos, but change
>> them so they read as follows:
>> 
>>  if (!dwc->regset)
>>  goto err1;
>> 
>>  [...]
>> 
>> return; /* this is our successful exit point */
>> 
>> err1:
>>  debugfs_remove_recursive(root);
>> kfree(dwc->regset);
>> 
>> 
>> --
>> Balbi
>
> No, no need anymore. Because no branch share this code now.
> Then remove the goto would make code a little clear.

fair enough.

-- 
balbi


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RE: [PATCH v3 1/2] usb: dwc3: make dwc3_debugfs_init return value be void

[Du, Changbin]

> > root = debugfs_create_dir(dev_name(dwc->dev), NULL);
> > -   if (!root) {
> > -   ret = -ENOMEM;
> > -   goto err0;
> > -   }
> > +   if (IS_ERR_OR_NULL(root))
> > +   return;
> 
> We can definitely keep on going, but I'd still like to know that we
> enabled CONFIG_DEBUG_FS but failed to create a file or a
> directory. Seems like this should read as follows:
> 
>   if (IS_ERR_OR_NULL(root)) {
>   if (!root)
>   dev_err(dwc->dev, "Can't create debugfs root\n");
>   return;
>   }
> 
> ditto to all bellow.
> 
Balbi, so you mean we should not let the failure go silent,  right?

> > dwc->root = root;
> >
> > dwc->regset = kzalloc(sizeof(*dwc->regset), GFP_KERNEL);
> > if (!dwc->regset) {
> > -   ret = -ENOMEM;
> > -   goto err1;
> > +   debugfs_remove_recursive(root);
> 
> you're now duplicating debugfs_remove_recursive(root) in all braches and
> that's error prone. It's probably better to keep our gotos, but change
> them so they read as follows:
> 
>   if (!dwc->regset)
>   goto err1;
> 
>   [...]
> 
> return; /* this is our successful exit point */
> 
> err1:
>   debugfs_remove_recursive(root);
> kfree(dwc->regset);
> 
> 
> --
> Balbi

No, no need anymore. Because no branch share this code now.
Then remove the goto would make code a little clear.

Thanks,
Du, Changbin

RE: [PATCH v3 1/2] usb: dwc3: make dwc3_debugfs_init return value be void

[Du, Changbin]

> > root = debugfs_create_dir(dev_name(dwc->dev), NULL);
> > -   if (!root) {
> > -   ret = -ENOMEM;
> > -   goto err0;
> > -   }
> > +   if (IS_ERR_OR_NULL(root))
> > +   return;
> 
> We can definitely keep on going, but I'd still like to know that we
> enabled CONFIG_DEBUG_FS but failed to create a file or a
> directory. Seems like this should read as follows:
> 
>   if (IS_ERR_OR_NULL(root)) {
>   if (!root)
>   dev_err(dwc->dev, "Can't create debugfs root\n");
>   return;
>   }
> 
> ditto to all bellow.
> 
Balbi, so you mean we should not let the failure go silent,  right?

> > dwc->root = root;
> >
> > dwc->regset = kzalloc(sizeof(*dwc->regset), GFP_KERNEL);
> > if (!dwc->regset) {
> > -   ret = -ENOMEM;
> > -   goto err1;
> > +   debugfs_remove_recursive(root);
> 
> you're now duplicating debugfs_remove_recursive(root) in all braches and
> that's error prone. It's probably better to keep our gotos, but change
> them so they read as follows:
> 
>   if (!dwc->regset)
>   goto err1;
> 
>   [...]
> 
> return; /* this is our successful exit point */
> 
> err1:
>   debugfs_remove_recursive(root);
> kfree(dwc->regset);
> 
> 
> --
> Balbi

No, no need anymore. Because no branch share this code now.
Then remove the goto would make code a little clear.

Thanks,
Du, Changbin

Re: [PATCH v3 1/2] usb: dwc3: make dwc3_debugfs_init return value be void

[Felipe Balbi]

Hi,

changbin...@intel.com writes:
> diff --git a/drivers/usb/dwc3/debug.h b/drivers/usb/dwc3/debug.h
> index 07fbc2d..71e3180 100644
> --- a/drivers/usb/dwc3/debug.h
> +++ b/drivers/usb/dwc3/debug.h
> @@ -217,11 +217,11 @@ static inline const char 
> *dwc3_gadget_event_type_string(u8 event)
>  void dwc3_trace(void (*trace)(struct va_format *), const char *fmt, ...);
>  
>  #ifdef CONFIG_DEBUG_FS
> -extern int dwc3_debugfs_init(struct dwc3 *);
> +extern void dwc3_debugfs_init(struct dwc3 *);
>  extern void dwc3_debugfs_exit(struct dwc3 *);
>  #else
> -static inline int dwc3_debugfs_init(struct dwc3 *d)
> -{  return 0;  }
> +static inline void dwc3_debugfs_init(struct dwc3 *d)
> +{  }
>  static inline void dwc3_debugfs_exit(struct dwc3 *d)
>  {  }
>  #endif
> diff --git a/drivers/usb/dwc3/debugfs.c b/drivers/usb/dwc3/debugfs.c
> index 9ac37fe..071b286 100644
> --- a/drivers/usb/dwc3/debugfs.c
> +++ b/drivers/usb/dwc3/debugfs.c
> @@ -618,69 +618,39 @@ static const struct file_operations 
> dwc3_link_state_fops = {
>   .release= single_release,
>  };
>  
> -int dwc3_debugfs_init(struct dwc3 *dwc)
> +void dwc3_debugfs_init(struct dwc3 *dwc)
>  {
>   struct dentry   *root;
> - struct dentry   *file;
> - int ret;
>  
>   root = debugfs_create_dir(dev_name(dwc->dev), NULL);
> - if (!root) {
> - ret = -ENOMEM;
> - goto err0;
> - }
> + if (IS_ERR_OR_NULL(root))
> + return;

We can definitely keep on going, but I'd still like to know that we
enabled CONFIG_DEBUG_FS but failed to create a file or a
directory. Seems like this should read as follows:

if (IS_ERR_OR_NULL(root)) {
if (!root)
dev_err(dwc->dev, "Can't create debugfs root\n");
return;
}

ditto to all bellow.

>   dwc->root = root;
>  
>   dwc->regset = kzalloc(sizeof(*dwc->regset), GFP_KERNEL);
>   if (!dwc->regset) {
> - ret = -ENOMEM;
> - goto err1;
> + debugfs_remove_recursive(root);

you're now duplicating debugfs_remove_recursive(root) in all braches and
that's error prone. It's probably better to keep our gotos, but change
them so they read as follows:

if (!dwc->regset)
goto err1;

[...]

return; /* this is our successful exit point */

err1:
debugfs_remove_recursive(root);
kfree(dwc->regset);


-- 
balbi


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Re: [PATCH v3 1/2] usb: dwc3: make dwc3_debugfs_init return value be void

[Felipe Balbi]

Hi,

changbin...@intel.com writes:
> diff --git a/drivers/usb/dwc3/debug.h b/drivers/usb/dwc3/debug.h
> index 07fbc2d..71e3180 100644
> --- a/drivers/usb/dwc3/debug.h
> +++ b/drivers/usb/dwc3/debug.h
> @@ -217,11 +217,11 @@ static inline const char 
> *dwc3_gadget_event_type_string(u8 event)
>  void dwc3_trace(void (*trace)(struct va_format *), const char *fmt, ...);
>  
>  #ifdef CONFIG_DEBUG_FS
> -extern int dwc3_debugfs_init(struct dwc3 *);
> +extern void dwc3_debugfs_init(struct dwc3 *);
>  extern void dwc3_debugfs_exit(struct dwc3 *);
>  #else
> -static inline int dwc3_debugfs_init(struct dwc3 *d)
> -{  return 0;  }
> +static inline void dwc3_debugfs_init(struct dwc3 *d)
> +{  }
>  static inline void dwc3_debugfs_exit(struct dwc3 *d)
>  {  }
>  #endif
> diff --git a/drivers/usb/dwc3/debugfs.c b/drivers/usb/dwc3/debugfs.c
> index 9ac37fe..071b286 100644
> --- a/drivers/usb/dwc3/debugfs.c
> +++ b/drivers/usb/dwc3/debugfs.c
> @@ -618,69 +618,39 @@ static const struct file_operations 
> dwc3_link_state_fops = {
>   .release= single_release,
>  };
>  
> -int dwc3_debugfs_init(struct dwc3 *dwc)
> +void dwc3_debugfs_init(struct dwc3 *dwc)
>  {
>   struct dentry   *root;
> - struct dentry   *file;
> - int ret;
>  
>   root = debugfs_create_dir(dev_name(dwc->dev), NULL);
> - if (!root) {
> - ret = -ENOMEM;
> - goto err0;
> - }
> + if (IS_ERR_OR_NULL(root))
> + return;

We can definitely keep on going, but I'd still like to know that we
enabled CONFIG_DEBUG_FS but failed to create a file or a
directory. Seems like this should read as follows:

if (IS_ERR_OR_NULL(root)) {
if (!root)
dev_err(dwc->dev, "Can't create debugfs root\n");
return;
}

ditto to all bellow.

>   dwc->root = root;
>  
>   dwc->regset = kzalloc(sizeof(*dwc->regset), GFP_KERNEL);
>   if (!dwc->regset) {
> - ret = -ENOMEM;
> - goto err1;
> + debugfs_remove_recursive(root);

you're now duplicating debugfs_remove_recursive(root) in all braches and
that's error prone. It's probably better to keep our gotos, but change
them so they read as follows:

if (!dwc->regset)
goto err1;

[...]

return; /* this is our successful exit point */

err1:
debugfs_remove_recursive(root);
kfree(dwc->regset);


-- 
balbi


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