Re: [PATCH net-next 2/3] net: dsa: vsc73xx: implement packet reception via control interface

From: kernel test robot
Date: Mon Oct 21 2024 - 22:19:22 EST


Hi Pawel,

kernel test robot noticed the following build warnings:

[auto build test WARNING on net-next/main]

url: https://github.com/intel-lab-lkp/linux/commits/Pawel-Dembicki/net-dsa-vsc73xx-implement-packet-reception-via-control-interface/20241021-050041
base: net-next/main
patch link: https://lore.kernel.org/r/20241020205452.2660042-2-paweldembicki%40gmail.com
patch subject: [PATCH net-next 2/3] net: dsa: vsc73xx: implement packet reception via control interface
config: x86_64-allyesconfig (https://download.01.org/0day-ci/archive/20241022/202410220908.uFiUPMGy-lkp@xxxxxxxxx/config)
compiler: clang version 18.1.8 (https://github.com/llvm/llvm-project 3b5b5c1ec4a3095ab096dd780e84d7ab81f3d7ff)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20241022/202410220908.uFiUPMGy-lkp@xxxxxxxxx/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@xxxxxxxxx>
| Closes: https://lore.kernel.org/oe-kbuild-all/202410220908.uFiUPMGy-lkp@xxxxxxxxx/

All warnings (new ones prefixed by >>):

>> drivers/net/dsa/vitesse-vsc73xx-core.c:935:30: warning: variable 'len' is uninitialized when used here [-Wuninitialized]
935 | skb = netdev_alloc_skb(dev, len);
| ^~~
drivers/net/dsa/vitesse-vsc73xx-core.c:885:23: note: initialize the variable 'len' to silence this warning
885 | int ret, buf_len, len, part;
| ^
| = 0
1 warning generated.


vim +/len +935 drivers/net/dsa/vitesse-vsc73xx-core.c

879
880 static void vsc73xx_polled_rcv(struct kthread_work *work)
881 {
882 struct vsc73xx *vsc = container_of(work, struct vsc73xx, dwork.work);
883 u16 ptr = VSC73XX_CAPT_FRAME_DATA;
884 struct dsa_switch *ds = vsc->ds;
885 int ret, buf_len, len, part;
886 struct vsc73xx_ifh ifh;
887 struct net_device *dev;
888 struct dsa_port *dp;
889 struct sk_buff *skb;
890 u32 val, *buf;
891 u16 count;
892
893 ret = vsc73xx_read(vsc, VSC73XX_BLOCK_SYSTEM, 0, VSC73XX_CAPCTRL, &val);
894 if (ret)
895 goto queue;
896
897 if (!(val & VSC73XX_CAPCTRL_QUEUE0_READY))
898 /* No frame to read */
899 goto queue;
900
901 /* Initialise reading */
902 ret = vsc73xx_read(vsc, VSC73XX_BLOCK_CAPTURE, VSC73XX_BLOCK_CAPT_Q0,
903 VSC73XX_CAPT_CAPREADP, &val);
904 if (ret)
905 goto queue;
906
907 /* Get internal frame header */
908 ret = vsc73xx_read(vsc, VSC73XX_BLOCK_CAPTURE,
909 VSC73XX_BLOCK_CAPT_FRAME0, ptr++, &ifh.datah);
910 if (ret)
911 goto queue;
912
913 ret = vsc73xx_read(vsc, VSC73XX_BLOCK_CAPTURE,
914 VSC73XX_BLOCK_CAPT_FRAME0, ptr++, &ifh.datal);
915 if (ret)
916 goto queue;
917
918 if (ifh.magic != VSC73XX_IFH_MAGIC) {
919 /* Something goes wrong with buffer. Reset capture block */
920 vsc73xx_write(vsc, VSC73XX_BLOCK_CAPTURE,
921 VSC73XX_BLOCK_CAPT_RST, VSC73XX_CAPT_CAPRST, 1);
922 goto queue;
923 }
924
925 if (!dsa_is_user_port(ds, ifh.port))
926 goto release_frame;
927
928 dp = dsa_to_port(ds, ifh.port);
929 dev = dp->user;
930 if (!dev)
931 goto release_frame;
932
933 count = (ifh.frame_length + 7 + VSC73XX_IFH_SIZE - ETH_FCS_LEN) >> 2;
934
> 935 skb = netdev_alloc_skb(dev, len);
936 if (unlikely(!skb)) {
937 netdev_err(dev, "Unable to allocate sk_buff\n");
938 goto release_frame;
939 }
940
941 buf_len = ifh.frame_length - ETH_FCS_LEN;
942 buf = (u32 *)skb_put(skb, buf_len);
943 len = 0;
944 part = 0;
945
946 while (ptr < count) {
947 ret = vsc73xx_read(vsc, VSC73XX_BLOCK_CAPTURE,
948 VSC73XX_BLOCK_CAPT_FRAME0 + part, ptr++,
949 buf + len);
950 if (ret)
951 goto free_skb;
952 len++;
953 if (ptr > VSC73XX_CAPT_FRAME_DATA_MAX &&
954 count != VSC73XX_CAPT_FRAME_DATA_MAX) {
955 ptr = VSC73XX_CAPT_FRAME_DATA;
956 part++;
957 count -= VSC73XX_CAPT_FRAME_DATA_MAX;
958 }
959 }
960
961 /* Get FCS */
962 ret = vsc73xx_read(vsc, VSC73XX_BLOCK_CAPTURE,
963 VSC73XX_BLOCK_CAPT_FRAME0, ptr++, &val);
964 if (ret)
965 goto free_skb;
966
967 /* Everything we see on an interface that is in the HW bridge
968 * has already been forwarded.
969 */
970 if (dp->bridge)
971 skb->offload_fwd_mark = 1;
972
973 skb->protocol = eth_type_trans(skb, dev);
974
975 netif_rx(skb);
976 goto release_frame;
977
978 free_skb:
979 kfree_skb(skb);
980 release_frame:
981 /* Release the frame from internal buffer */
982 vsc73xx_write(vsc, VSC73XX_BLOCK_CAPTURE, VSC73XX_BLOCK_CAPT_Q0,
983 VSC73XX_CAPT_CAPREADP, 0);
984 queue:
985 kthread_queue_delayed_work(vsc->rcv_worker, &vsc->dwork,
986 msecs_to_jiffies(VSC73XX_RCV_POLL_INTERVAL));
987 }
988

--
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki