Hello Heikki Krogerus,
Commit 100e25738659 ("usb: typec: Add driver for Thunderbolt 3
Alternate Mode") from Dec 13, 2024 (linux-next), leads to the
following (unpublished) Smatch static checker warnings:
drivers/usb/typec/altmodes/thunderbolt.c:116 tbt_altmode_work() warn: why is zero skipped 'i'
drivers/usb/typec/altmodes/thunderbolt.c:147 tbt_enter_modes_ordered() warn: why is zero skipped 'i'
drivers/usb/typec/altmodes/thunderbolt.c:153 tbt_enter_modes_ordered() info: return a literal instead of 'ret'
drivers/usb/typec/altmodes/thunderbolt.c:328 tbt_altmode_remove() warn: why is zero skipped 'i'
drivers/usb/typec/altmodes/thunderbolt.c:354 tbt_ready() warn: 'plug' is not an error pointer
drivers/usb/typec/altmodes/thunderbolt.c
66 static void tbt_altmode_work(struct work_struct *work)
67 {
68 struct tbt_altmode *tbt = container_of(work, struct tbt_altmode, work);
69 int ret;
70
71 mutex_lock(&tbt->lock);
72
73 switch (tbt->state) {
74 case TBT_STATE_SOP_P_ENTER:
75 ret = typec_cable_altmode_enter(tbt->alt, TYPEC_PLUG_SOP_P, NULL);
76 if (ret) {
77 dev_dbg(&tbt->plug[TYPEC_PLUG_SOP_P]->dev,
78 "failed to enter mode (%d)\n", ret);
79 goto disable_plugs;
80 }
81 break;
82 case TBT_STATE_SOP_PP_ENTER:
83 ret = typec_cable_altmode_enter(tbt->alt, TYPEC_PLUG_SOP_PP, NULL);
84 if (ret) {
85 dev_dbg(&tbt->plug[TYPEC_PLUG_SOP_PP]->dev,
86 "failed to enter mode (%d)\n", ret);
87 goto disable_plugs;
88 }
89 break;
90 case TBT_STATE_ENTER:
91 ret = tbt_enter_mode(tbt);
92 if (ret)
93 dev_dbg(&tbt->alt->dev, "failed to enter mode (%d)\n",
94 ret);
95 break;
96 case TBT_STATE_EXIT:
97 typec_altmode_exit(tbt->alt);
98 break;
99 case TBT_STATE_SOP_PP_EXIT:
100 typec_cable_altmode_exit(tbt->alt, TYPEC_PLUG_SOP_PP);
101 break;
102 case TBT_STATE_SOP_P_EXIT:
103 typec_cable_altmode_exit(tbt->alt, TYPEC_PLUG_SOP_P);
104 break;
105 default:
106 break;
107 }
108
109 tbt->state = TBT_STATE_IDLE;
110
111 mutex_unlock(&tbt->lock);
112 return;
113
114 disable_plugs:
115 for (int i = TYPEC_PLUG_SOP_PP; i > 0; --i) {
^^^^^
These should be >= 0. Humans are bad at counting backwards.
--> 116 if (tbt->plug[i])
117 typec_altmode_put_plug(tbt->plug[i]);
118
119 tbt->plug[i] = NULL;
120 }
121
122 tbt->state = TBT_STATE_ENTER;
123 schedule_work(&tbt->work);
124 mutex_unlock(&tbt->lock);
125 }
regards,
dan carpenter
