Hello William Qiu,
The patch 9e622229bbf4: "mmc: starfive: Add sdio/emmc driver support"
from Feb 15, 2023, leads to the following Smatch static checker
warning:
drivers/mmc/host/dw_mmc-starfive.c:77 dw_mci_starfive_execute_tuning()
error: uninitialized symbol 'prev_err'.
drivers/mmc/host/dw_mmc-starfive.c
47 static int dw_mci_starfive_execute_tuning(struct dw_mci_slot *slot,
48 u32 opcode)
49 {
50 static const int grade = MAX_DELAY_CHAIN;
51 struct dw_mci *host = slot->host;
52 struct starfive_priv *priv = host->priv;
53 int rise_point = -1, fall_point = -1;
54 int err, prev_err;
55 int i;
56 bool found = 0;
57 u32 regval;
58
59 /*
60 * Use grade as the max delay chain, and use the rise_point and
61 * fall_point to ensure the best sampling point of a data input
62 * signals.
63 */
64 for (i = 0; i < grade; i++) {
65 regval = i << priv->syscon_shift;
66 err = regmap_update_bits(priv->reg_syscon, priv->syscon_offset,
67 priv->syscon_mask, regval);
68 if (err)
69 return err;
70 mci_writel(host, RINTSTS, ALL_INT_CLR);
71
72 err = mmc_send_tuning(slot->mmc, opcode, NULL);
73 if (!err)
74 found = 1;
75
76 if (i > 0) {
--> 77 if (err && !prev_err)
prev_err was never initialized to zero.
78 fall_point = i - 1;
79 if (!err && prev_err)
80 rise_point = i;
81 }
82
83 if (rise_point != -1 && fall_point != -1)
84 goto tuning_out;
85
86 prev_err = err;
87 err = 0;
88 }
89
regards,
dan carpenter
