[bug report] mmc: renesas_sdhi: abort tuning when timeout detected

[bug report] mmc: renesas_sdhi: abort tuning when timeout detected

[Dan Carpenter]

Hello Wolfram Sang,

The patch 2c9017d0b5d3: "mmc: renesas_sdhi: abort tuning when timeout
detected" from Jun 2, 2021, leads to the following Smatch static
checker warning:

	drivers/mmc/host/renesas_sdhi_core.c:701 renesas_sdhi_execute_tuning()
	error: uninitialized symbol 'cmd_error'.

drivers/mmc/host/renesas_sdhi_core.c
    669 static int renesas_sdhi_execute_tuning(struct mmc_host *mmc, u32 opcode)
    670 {
    671         struct tmio_mmc_host *host = mmc_priv(mmc);
    672         struct renesas_sdhi *priv = host_to_priv(host);
    673         int i, ret;
    674 
    675         priv->tap_num = renesas_sdhi_init_tuning(host);
    676         if (!priv->tap_num)
    677                 return 0; /* Tuning is not supported */
    678 
    679         if (priv->tap_num * 2 >= sizeof(priv->taps) * BITS_PER_BYTE) {
    680                 dev_err(&host->pdev->dev,
    681                         "Too many taps, please update 'taps' in tmio_mmc_host!\n");
    682                 return -EINVAL;
    683         }
    684 
    685         bitmap_zero(priv->taps, priv->tap_num * 2);
    686         bitmap_zero(priv->smpcmp, priv->tap_num * 2);
    687 
    688         /* Issue CMD19 twice for each tap */
    689         for (i = 0; i < 2 * priv->tap_num; i++) {
    690                 int cmd_error;
                        ^^^^^^^^^^^^^

    691 
    692                 /* Set sampling clock position */
    693                 sd_scc_write32(host, priv, SH_MOBILE_SDHI_SCC_TAPSET, i % priv->tap_num);
    694 
    695                 if (mmc_send_tuning(mmc, opcode, &cmd_error) == 0)
                                                         ^^^^^^^^^^
This is not necessarily initialized on some error paths in mmc_send_tuning()

    696                         set_bit(i, priv->taps);
    697 
    698                 if (sd_scc_read32(host, priv, SH_MOBILE_SDHI_SCC_SMPCMP) == 0)
    699                         set_bit(i, priv->smpcmp);
    700 
--> 701                 if (cmd_error)
                            ^^^^^^^^^
warning.

    702                         mmc_send_abort_tuning(mmc, opcode);
    703         }
    704 
    705         ret = renesas_sdhi_select_tuning(host);
    706         if (ret < 0)
    707                 renesas_sdhi_scc_reset(host, priv);
    708         return ret;
    709 }

regards,
dan carpenter

Re: [bug report] mmc: renesas_sdhi: abort tuning when timeout detected

[Wolfram Sang]

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>     695                 if (mmc_send_tuning(mmc, opcode, &cmd_error) == 0)
>                                                          ^^^^^^^^^^
> This is not necessarily initialized on some error paths in mmc_send_tuning()

True. Thanks Dan for the report, I will send a fix.


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