From mboxrd@z Thu Jan  1 00:00:00 1970
From: Ajay.Kathat@microchip.com (Ajay.Kathat@microchip.com)
Date: Tue, 13 Aug 2019 06:25:58 +0000
Subject: [bug report] staging: wilc1000: added support to dynamically
 add/remove interfaces
In-Reply-To: <20190808104831.GA854@mwanda>
References: <20190808104831.GA854@mwanda>
Message-ID: <6eb384fc-4acc-c9e4-2c15-c8862120c8ec@microchip.com>
List-Id: Linux Driver Project Developer List
 <driverdev-devel.linuxdriverproject.org>

Hi Dan,

On 8/8/2019 4:18 PM, Dan Carpenter wrote:
> 
> Hello Ajay Singh,
> 
> The patch 9bc061e88054: "staging: wilc1000: added support to
> dynamically add/remove interfaces" from Jun 26, 2019, leads to the
> following static checker warning:
> 
> 	drivers/staging/wilc1000/wilc_wlan.c:497 wilc_wlan_handle_txq()
> 	warn: missing error code here? 'wilc_wlan_txq_get_first()' failed.
> 
> drivers/staging/wilc1000/wilc_wlan.c
>    474  int wilc_wlan_handle_txq(struct wilc *wilc, u32 *txq_count)
>    475  {
>    476          int i, entries = 0;
>    477          u32 sum;
>    478          u32 reg;
>    479          u32 offset = 0;
>    480          int vmm_sz = 0;
>    481          struct txq_entry_t *tqe;
>    482          int ret = 0;
>                     ^^^^^^^
> 
>    483          int counter;
>    484          int timeout;
>    485          u32 vmm_table[WILC_VMM_TBL_SIZE];
>    486          const struct wilc_hif_func *func;
>    487          u8 *txb = wilc->tx_buffer;
>    488          struct net_device *dev;
>    489          struct wilc_vif *vif;
>    490  
>    491          if (wilc->quit)
>    492                  goto out;
>    493  
>    494          mutex_lock(&wilc->txq_add_to_head_cs);
>    495          tqe = wilc_wlan_txq_get_first(wilc);
>    496          if (!tqe)
>    497                  goto out;
>                         ^^^^^^^^
> Should this really be a success path?

I think, returning value '0' is safe here. Only 'ENOBUFS' return value
is used for retry while other values are not considered. The 'if'
condition exit this function in case the list is empty. And later the
elements will be fetched again once'txq_event' completion signal is
received.

Regards,
Ajay