[linux-next:master 11640/13394] drivers/net/can/usb/peak_usb/pcan_usb.c:852:9: warning: Variable 'pc' is modified but its new value is never used. [unreadVariable]

[linux-next:master 11640/13394] drivers/net/can/usb/peak_usb/pcan_usb.c:852:9: warning: Variable 'pc' is modified but its new value is never used. [unreadVariable]

[kernel test robot]

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CC: kbuild-all(a)lists.01.org
CC: Linux Memory Management List <linux-mm@kvack.org>
TO: "Marc Kleine-Budde" <mkl@pengutronix.de>

tree:   https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git master
head:   18250b538735142307082e4e99e3ae5c12d44013
commit: bd573ea5720470d1ea70f3e39fb2e2efad219311 [11640/13394] can: peak_usb: pcan_usb: replace open coded endianness conversion of unaligned data
:::::: branch date: 18 hours ago
:::::: commit date: 4 days ago
compiler: h8300-linux-gcc (GCC) 9.3.0

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>


cppcheck possible warnings: (new ones prefixed by >>, may not real problems)

>> drivers/net/can/usb/peak_usb/pcan_usb.c:852:9: warning: Variable 'pc' is modified but its new value is never used. [unreadVariable]
     pc += cf->len;
           ^

vim +/pc +852 drivers/net/can/usb/peak_usb/pcan_usb.c

46be265d338833 Stephane Grosjean 2012-03-02  812  
46be265d338833 Stephane Grosjean 2012-03-02  813  /*
46be265d338833 Stephane Grosjean 2012-03-02  814   * process outgoing packet
46be265d338833 Stephane Grosjean 2012-03-02  815   */
46be265d338833 Stephane Grosjean 2012-03-02  816  static int pcan_usb_encode_msg(struct peak_usb_device *dev, struct sk_buff *skb,
46be265d338833 Stephane Grosjean 2012-03-02  817  			       u8 *obuf, size_t *size)
46be265d338833 Stephane Grosjean 2012-03-02  818  {
46be265d338833 Stephane Grosjean 2012-03-02  819  	struct net_device *netdev = dev->netdev;
46be265d338833 Stephane Grosjean 2012-03-02  820  	struct net_device_stats *stats = &netdev->stats;
46be265d338833 Stephane Grosjean 2012-03-02  821  	struct can_frame *cf = (struct can_frame *)skb->data;
46be265d338833 Stephane Grosjean 2012-03-02  822  	u8 *pc;
46be265d338833 Stephane Grosjean 2012-03-02  823  
46be265d338833 Stephane Grosjean 2012-03-02  824  	obuf[0] = 2;
46be265d338833 Stephane Grosjean 2012-03-02  825  	obuf[1] = 1;
46be265d338833 Stephane Grosjean 2012-03-02  826  
46be265d338833 Stephane Grosjean 2012-03-02  827  	pc = obuf + PCAN_USB_MSG_HEADER_LEN;
46be265d338833 Stephane Grosjean 2012-03-02  828  
46be265d338833 Stephane Grosjean 2012-03-02  829  	/* status/len byte */
4c01fc87675e69 Oliver Hartkopp   2020-11-11  830  	*pc = can_get_cc_dlc(cf, dev->can.ctrlmode);
4c01fc87675e69 Oliver Hartkopp   2020-11-11  831  
46be265d338833 Stephane Grosjean 2012-03-02  832  	if (cf->can_id & CAN_RTR_FLAG)
46be265d338833 Stephane Grosjean 2012-03-02  833  		*pc |= PCAN_USB_STATUSLEN_RTR;
46be265d338833 Stephane Grosjean 2012-03-02  834  
46be265d338833 Stephane Grosjean 2012-03-02  835  	/* can id */
46be265d338833 Stephane Grosjean 2012-03-02  836  	if (cf->can_id & CAN_EFF_FLAG) {
46be265d338833 Stephane Grosjean 2012-03-02  837  		*pc |= PCAN_USB_STATUSLEN_EXT_ID;
bd573ea5720470 Marc Kleine-Budde 2021-04-05  838  		pc++;
bd573ea5720470 Marc Kleine-Budde 2021-04-05  839  
bd573ea5720470 Marc Kleine-Budde 2021-04-05  840  		put_unaligned_le32((cf->can_id & CAN_ERR_MASK) << 3, pc);
46be265d338833 Stephane Grosjean 2012-03-02  841  		pc += 4;
46be265d338833 Stephane Grosjean 2012-03-02  842  	} else {
bd573ea5720470 Marc Kleine-Budde 2021-04-05  843  		pc++;
46be265d338833 Stephane Grosjean 2012-03-02  844  
bd573ea5720470 Marc Kleine-Budde 2021-04-05  845  		put_unaligned_le16((cf->can_id & CAN_ERR_MASK) << 5, pc);
46be265d338833 Stephane Grosjean 2012-03-02  846  		pc += 2;
46be265d338833 Stephane Grosjean 2012-03-02  847  	}
46be265d338833 Stephane Grosjean 2012-03-02  848  
46be265d338833 Stephane Grosjean 2012-03-02  849  	/* can data */
46be265d338833 Stephane Grosjean 2012-03-02  850  	if (!(cf->can_id & CAN_RTR_FLAG)) {
c7b74967799b1a Oliver Hartkopp   2020-11-20  851  		memcpy(pc, cf->data, cf->len);
c7b74967799b1a Oliver Hartkopp   2020-11-20 @852  		pc += cf->len;
46be265d338833 Stephane Grosjean 2012-03-02  853  	}
46be265d338833 Stephane Grosjean 2012-03-02  854  
46be265d338833 Stephane Grosjean 2012-03-02  855  	obuf[(*size)-1] = (u8)(stats->tx_packets & 0xff);
46be265d338833 Stephane Grosjean 2012-03-02  856  
46be265d338833 Stephane Grosjean 2012-03-02  857  	return 0;
46be265d338833 Stephane Grosjean 2012-03-02  858  }
46be265d338833 Stephane Grosjean 2012-03-02  859  

:::::: The code at line 852 was first introduced by commit
:::::: c7b74967799b1af52b3045d69d4c26836b2d41de can: replace can_dlc as variable/element for payload length

:::::: TO: Oliver Hartkopp <socketcan@hartkopp.net>
:::::: CC: Marc Kleine-Budde <mkl@pengutronix.de>

---
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