Re: [PATCH v3] staging: vt6656: returns error code on vnt_int_start_interrupt fail

[Greg Kroah-Hartman <gregkh@linuxfoundation.org>]

On Fri, May 17, 2019 at 07:53:49AM +0000, Quentin Deslandes wrote:
> Returns error code from 'vnt_int_start_interrupt()' so the device's private
> buffers will be correctly freed and 'struct ieee80211_hw' start function
> will return an error code.
> 
> Signed-off-by: Quentin Deslandes <quentin.deslandes@itdev.co.uk>
> ---
> v2: returns 'status' value to caller instead of removing it.
> v3: add patch version details. Thanks to Greg K-H for his help.

Looking better!

But a few minor things below:

> 
>  drivers/staging/vt6656/int.c      |  4 +++-
>  drivers/staging/vt6656/int.h      |  2 +-
>  drivers/staging/vt6656/main_usb.c | 12 +++++++++---
>  3 files changed, 13 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/staging/vt6656/int.c b/drivers/staging/vt6656/int.c
> index 504424b19fcf..f3ee2198e1b3 100644
> --- a/drivers/staging/vt6656/int.c
> +++ b/drivers/staging/vt6656/int.c
> @@ -39,7 +39,7 @@ static const u8 fallback_rate1[5][5] = {
>  	{RATE_54M, RATE_54M, RATE_36M, RATE_18M, RATE_18M}
>  };
>  
> -void vnt_int_start_interrupt(struct vnt_private *priv)
> +int vnt_int_start_interrupt(struct vnt_private *priv)
>  {
>  	unsigned long flags;
>  	int status;
> @@ -51,6 +51,8 @@ void vnt_int_start_interrupt(struct vnt_private *priv)
>  	status = vnt_start_interrupt_urb(priv);
>  
>  	spin_unlock_irqrestore(&priv->lock, flags);
> +
> +	return status;
>  }
>  
>  static int vnt_int_report_rate(struct vnt_private *priv, u8 pkt_no, u8 tsr)
> diff --git a/drivers/staging/vt6656/int.h b/drivers/staging/vt6656/int.h
> index 987c454e99e9..8a6d60569ceb 100644
> --- a/drivers/staging/vt6656/int.h
> +++ b/drivers/staging/vt6656/int.h
> @@ -41,7 +41,7 @@ struct vnt_interrupt_data {
>  	u8 sw[2];
>  } __packed;
>  
> -void vnt_int_start_interrupt(struct vnt_private *priv);
> +int vnt_int_start_interrupt(struct vnt_private *priv);
>  void vnt_int_process_data(struct vnt_private *priv);
>  
>  #endif /* __INT_H__ */
> diff --git a/drivers/staging/vt6656/main_usb.c b/drivers/staging/vt6656/main_usb.c
> index ccafcc2c87ac..71e10b9ae253 100644
> --- a/drivers/staging/vt6656/main_usb.c
> +++ b/drivers/staging/vt6656/main_usb.c
> @@ -483,6 +483,7 @@ static void vnt_tx_80211(struct ieee80211_hw *hw,
>  
>  static int vnt_start(struct ieee80211_hw *hw)
>  {
> +	int err = 0;
>  	struct vnt_private *priv = hw->priv;
>  
>  	priv->rx_buf_sz = MAX_TOTAL_SIZE_WITH_ALL_HEADERS;
> @@ -496,15 +497,20 @@ static int vnt_start(struct ieee80211_hw *hw)
>  
>  	if (vnt_init_registers(priv) == false) {
>  		dev_dbg(&priv->usb->dev, " init register fail\n");
> +		err = -ENOMEM;

Why ENOMEM?  vnt_init_registers() should return a proper error code,
based on what went wrong, not true/false.  So fix that up first, and
then you can do this patch.

See, your one tiny coding style fix is turning into real cleanups, nice!

>  		goto free_all;
>  	}
>  
> -	if (vnt_key_init_table(priv))
> +	if (vnt_key_init_table(priv)) {
> +		err = -ENOMEM;

Same here, vnt_key_init_table() should return a real error value, and
then just return that here.

>  		goto free_all;
> +	}
>  
>  	priv->int_interval = 1;  /* bInterval is set to 1 */
>  
> -	vnt_int_start_interrupt(priv);
> +	err = vnt_int_start_interrupt(priv);
> +	if (err)
> +		goto free_all;

Like this, that is the correct thing.

So, this is now going to be a patch series, fixing up those two
functions (and any functions they call possibly), and then this can be
the last patch of the series.

thanks,

greg k-h