[bug report] net: libwx: Implement interaction with firmware

[bug report] net: libwx: Implement interaction with firmware

[Dan Carpenter]

Hello Jiawen Wu,

The patch 1efa9bfe58c5: "net: libwx: Implement interaction with
firmware" from Oct 31, 2022, leads to the following Smatch static
checker warning:

	drivers/net/ethernet/wangxun/libwx/wx_hw.c:210 wx_host_interface_command()
	warn: duplicate check 'status' (previous on line 206)

drivers/net/ethernet/wangxun/libwx/wx_hw.c
    200         /* Setting this bit tells the ARC that a new command is pending. */
    201         wr32m(wxhw, WX_MNG_MBOX_CTL,
    202               WX_MNG_MBOX_CTL_SWRDY, WX_MNG_MBOX_CTL_SWRDY);
    203 
    204         status = read_poll_timeout(rd32, hicr, hicr & WX_MNG_MBOX_CTL_FWRDY, 1000,
    205                                    timeout * 1000, false, wxhw, WX_MNG_MBOX_CTL);
    206         if (status)
                    ^^^^^^
Checked

    207                 goto rel_out;
    208 
    209         /* Check command completion */
--> 210         if (status) {
                    ^^^^^^
Dead code.

    211                 wx_dbg(wxhw, "Command has failed with no status valid.\n");
    212 
    213                 buf[0] = rd32(wxhw, WX_MNG_MBOX);
    214                 if ((buffer[0] & 0xff) != (~buf[0] >> 24)) {
    215                         status = -EINVAL;
    216                         goto rel_out;
    217                 }
    218                 if ((buf[0] & 0xff0000) >> 16 == 0x80) {
    219                         wx_dbg(wxhw, "It's unknown cmd.\n");
    220                         status = -EINVAL;
    221                         goto rel_out;
    222                 }
    223 
    224                 wx_dbg(wxhw, "write value:\n");
    225                 for (i = 0; i < dword_len; i++)
    226                         wx_dbg(wxhw, "%x ", buffer[i]);
    227                 wx_dbg(wxhw, "read value:\n");
    228                 for (i = 0; i < dword_len; i++)
    229                         wx_dbg(wxhw, "%x ", buf[i]);
    230         }
    231 
    232         if (!return_data)
    233                 goto rel_out;
    234 
    235         /* Calculate length in DWORDs */
    236         dword_len = hdr_size >> 2;
    237 
    238         /* first pull in the header so we know the buffer length */
    239         for (bi = 0; bi < dword_len; bi++) {
    240                 buffer[bi] = rd32a(wxhw, WX_MNG_MBOX, bi);
    241                 le32_to_cpus(&buffer[bi]);
    242         }
    243 
    244         /* If there is any thing in data position pull it in */
    245         buf_len = ((struct wx_hic_hdr *)buffer)->buf_len;
    246         if (buf_len == 0)
    247                 goto rel_out;
    248 
    249         if (length < buf_len + hdr_size) {
    250                 wx_err(wxhw, "Buffer not large enough for reply message.\n");
    251                 status = -EFAULT;
    252                 goto rel_out;
    253         }
    254 
    255         /* Calculate length in DWORDs, add 3 for odd lengths */
    256         dword_len = (buf_len + 3) >> 2;
    257 
    258         /* Pull in the rest of the buffer (bi is where we left off) */
    259         for (; bi <= dword_len; bi++) {
    260                 buffer[bi] = rd32a(wxhw, WX_MNG_MBOX, bi);
    261                 le32_to_cpus(&buffer[bi]);
    262         }
    263 
    264 rel_out:
    265         wx_release_sw_sync(wxhw, WX_MNG_SWFW_SYNC_SW_MB);
    266         return status;
    267 }

regards,
dan carpenter